Method and apparatus for performing cell reselection in wireless communication system

ABSTRACT

A method of operating a terminal and a base station in a wireless communication system and an apparatus supporting the same are disclosed. The method comprises receiving a first system information block (SIB) from a first base station—the received first SIB including at least one first parameter for a cell reselection learning model—, receiving radio channel environment information from the first base station, updating the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information, and performing cell reselection for a second base station based on the updated at least one second parameter.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/KR2021/005199, filed on Apr. 23, 2021, which claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2020-0111928, filed on Sep. 2, 2020, the contents of which are all hereby incorporated by reference herein in their entireties.

TECHNICAL FIELD

The following description relates to a wireless communication system, and relates to a method and apparatus for performing cell reselection in a wireless communication system.

BACKGROUND

Radio access systems have come into widespread in order to provide various types of communication services such as voice or data. In general, a radio access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmit power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, a single carrier-frequency division multiple access (SC-FDMA) system, etc.

In particular, as many communication apparatuses require a large communication capacity, an enhanced mobile broadband (eMBB) communication technology has been proposed compared to radio access technology (RAT). In addition, not only massive machine type communications (MTC) for providing various services anytime anywhere by connecting a plurality of apparatuses and things but also communication systems considering services/user equipments (UEs) sensitive to reliability and latency have been proposed. To this end, various technical configurations have been proposed.

SUMMARY

The present disclosure relates to a method and apparatus for more efficiently performing cell reselection in a wireless communication system.

The technical objects to be achieved in the present disclosure are not limited to the above-mentioned technical objects, and other technical objects that are not mentioned may be considered by those skilled in the art through the embodiments described below.

As an example of the present disclosure, an operation method of a terminal may include receiving a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The operation method of the terminal may include receiving radio channel environment information from the first base station. The operation method of the terminal may include updating the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information, and reselecting a second base station based on the updated at least one second parameter.

As an example of the present disclosure, an apparatus in a wireless communication system comprises a wireless transceiver. The wireless transceiver may receive a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The wireless transceiver may receive radio channel environment information from the first base station. The processor may update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information, and reselect a second base station based on the updated at least one second parameter.

As an example of the present disclosure, an operation method of a base station may include receiving parameter information related to a cell reselection learning model from a plurality of terminals. The operation method of the base station may include generating at least one first parameter for the cell reselection learning model based on the received parameter information. The operation method of the base station may include transmitting a system information block (SIB) including the at least one first parameter to a first terminal. The operation method of the base station may include transmitting radio channel environment information to the first terminal.

As an example of the present disclosure, a base station may comprise a transceiver and a processor connected to the transceiver. The transceiver may receive parameter information related to a cell reselection learning model from a plurality of terminals. The processor may generate at least one first parameter for the cell reselection learning model based on the received parameter information. The transceiver may transmit a system information block (SIB) including the at least one first parameter to a first terminal. The transceiver may transmit radio channel environment information to the first terminal.

As an example of the present disclosure, an apparatus may comprise at least one memory and at least one processor functionally connected to the at least one memory. The at least one processor may control the apparatus to receive a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The at least one processor may perform control to receive radio channel environment information from the first base station. The at least one processor may perform control to update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information. The at least one processor may perform control to perform cell reselection for a second base station based on the updated at least one second parameter.

As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction may comprise at least one instruction executable by a processor. The at least one instruction may instruct the computer-readable medium to receive a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The at least one instruction may instruct the computer-readable medium to receive radio channel environment information from the first base station. The at least one instruction may instruct the computer-readable medium to update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information. The at least one instruction may instruct the computer-readable medium to perform cell reselection for a second base station based on the updated at least one second parameter.

The above-described aspects of the present disclosure are only a part of the preferred embodiments of the present disclosure, and various embodiments reflecting technical features of the present disclosure may be derived and understood by those skilled in the art on the basis of the detailed description of the present disclosure provided below.

The following effects may be produced by embodiments based on the present disclosure.

According to the present disclosure, a terminal can efficiently perform cell reselection in a wireless communication system.

According to the present disclosure, a terminal can efficiently access a base station by using information accessed by other terminals in a wireless communication system.

According to the present disclosure, it is possible to reduce power consumption of a terminal by reducing an attempt of a terminal to access a base station in a wireless communication system.

According to the present disclosure, it is possible to enable a base station to efficiently manage resources by reducing an attempt of a terminal to access a base station in a wireless communication system.

According to the present disclosure, it is possible to reduce overlap between a base station and a repeater in a wireless communication system.

Effects obtained in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly derived and understood by those skilled in the art, to which a technical configuration of the present disclosure is applied, from the following description of embodiments of the present disclosure. That is, effects, which are not intended when implementing a configuration described in the present disclosure, may also be derived by those skilled in the art from the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are provided to aid understanding of the present disclosure, and embodiments of the present disclosure may be provided together with a detailed description. However, the technical features of the present disclosure are not limited to a specific drawing, and features disclosed in each drawing may be combined with each other to constitute a new embodiment. Reference numerals in each drawing may mean structural elements.

FIG. 1 is a view showing an example of a communication system applicable to the present disclosure.

FIG. 2 is a view showing an example of a wireless device applicable to the present disclosure.

FIG. 3 is a view showing another example of a wireless device applicable to the present disclosure.

FIG. 4 is a view showing an example of a hand-held device applicable to the present disclosure.

FIG. 5 is a view showing an example of a car or an autonomous driving car applicable to the present disclosure.

FIG. 6 is a view showing an example of a mobility applicable to the present disclosure.

FIG. 7 is a view showing an example of an extended reality (XR) device applicable to the present disclosure.

FIG. 8 is a view showing an example of a robot applicable to the present disclosure.

FIG. 9 is a view showing an example of artificial intelligence (AI) device applicable to the present disclosure.

FIG. 10 is a view showing physical channels applicable to the present disclosure and a signal transmission method using the same.

FIG. 11 is a view showing the structure of a control plane and a user plane of a radio interface protocol applicable to the present disclosure.

FIG. 12 is a view showing a method of processing a transmitted signal applicable to the present disclosure.

FIG. 13 is a view showing the structure of a radio frame applicable to the present disclosure.

FIG. 14 is a view showing a slot structure applicable to the present disclosure.

FIG. 15 is a view showing an example of a communication structure providable in a 6th generation (6G) system applicable to the present disclosure.

FIG. 16 is a view showing an electromagnetic spectrum applicable to the present disclosure.

FIG. 17 is a view showing a THz communication method applicable to the present disclosure.

FIG. 18 is a view showing a THz wireless communication transceiver applicable to the present disclosure.

FIG. 19 is a view showing a THz signal generation method applicable to the present disclosure.

FIG. 20 is a view showing a wireless communication transceiver applicable to the present disclosure.

FIG. 21 is a view showing a transmitter structure applicable to the present disclosure.

FIG. 22 is a view showing a modulator structure applicable to the present disclosure.

FIG. 23 is a view showing a perceptron architecture in an artificial neural network applicable to the present disclosure.

FIG. 24 is a view showing an artificial neural network architecture applicable to the present disclosure.

FIG. 25 is a view showing a deep neural network applicable to the present disclosure.

FIG. 26 is a view showing a convolutional neural network applicable to the present disclosure.

FIG. 27 is a view showing a filter operation of a convolutional neural network applicable to the present disclosure.

FIG. 28 is a view showing a neural network architecture with a recurrent loop applicable to the present disclosure.

FIG. 29 is a view showing an operational structure of a recurrent neural network applicable to the present disclosure.

FIG. 29 is a view showing an operational structure of a recurrent neural network applicable to the present disclosure.

FIG. 30 is a diagram illustrating information for cell reselection applicable to the present disclosure.

FIG. 31 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 32 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 33 is a diagram illustrating a federated learning procedure of multiple terminals applicable to the present disclosure.

FIG. 34 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 35 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 36 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 37 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure.

FIG. 38 is a diagram illustrating an example of a parameter predictor applicable to the present disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure described below are combinations of elements and features of the present disclosure in specific forms. The elements or features may be considered selective unless otherwise mentioned. Each element or feature may be practiced without being combined with other elements or features. Further, an embodiment of the present disclosure may be constructed by combining parts of the elements and/or features. Operation orders described in embodiments of the present disclosure may be rearranged. Some constructions or elements of any one embodiment may be included in another embodiment and may be replaced with corresponding constructions or features of another embodiment.

In the description of the drawings, procedures or steps which render the scope of the present disclosure unnecessarily ambiguous will be omitted and procedures or steps which can be understood by those skilled in the art will be omitted.

Throughout the specification, when a certain portion “includes” or “comprises” a certain component, this indicates that other components are not excluded and may be further included unless otherwise noted. The terms “unit”, “-or/er” and “module” described in the specification indicate a unit for processing at least one function or operation, which may be implemented by hardware, software or a combination thereof. In addition, the terms “a or an”, “one”, “the” etc. may include a singular representation and a plural representation in the context of the present disclosure (more particularly, in the context of the following claims) unless indicated otherwise in the specification or unless context clearly indicates otherwise.

In the embodiments of the present disclosure, a description is mainly made of a data transmission and reception relationship between a base station (BS) and a mobile station. ABS refers to a terminal node of a network, which directly communicates with a mobile station. A specific operation described as being performed by the BS may be performed by an upper node of the BS.

Namely, it is apparent that, in a network comprised of a plurality of network nodes including a BS, various operations performed for communication with a mobile station may be performed by the BS, or network nodes other than the BS. The term “BS” may be replaced with a fixed station, a Node B, an evolved Node B (eNode B or eNB), an advanced base station (ABS), an access point, etc.

In the embodiments of the present disclosure, the term terminal may be replaced with a UE, a mobile station (MS), a subscriber station (SS), a mobile subscriber station (MSS), a mobile terminal, an advanced mobile station (AMS), etc.

A transmitter is a fixed and/or mobile node that provides a data service or a voice service and a receiver is a fixed and/or mobile node that receives a data service or a voice service. Therefore, a mobile station may serve as a transmitter and a BS may serve as a receiver, on an uplink (UL). Likewise, the mobile station may serve as a receiver and the BS may serve as a transmitter, on a downlink (DL).

The embodiments of the present disclosure may be supported by standard specifications disclosed for at least one of wireless access systems including an Institute of Electrical and Electronics Engineers (IEEE) 802.xx system, a 3rd Generation Partnership Project (3GPP) system, a 3GPP Long Term Evolution (LTE) system, 3GPP 5th generation (5G) new radio (NR) system, and a 3GPP2 system. In particular, the embodiments of the present disclosure may be supported by the standard specifications, 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321 and 3GPP TS 36.331.

In addition, the embodiments of the present disclosure are applicable to other radio access systems and are not limited to the above-described system. For example, the embodiments of the present disclosure are applicable to systems applied after a 3GPP 5G NR system and are not limited to a specific system.

That is, steps or parts that are not described to clarify the technical features of the present disclosure may be supported by those documents. Further, all terms as set forth herein may be explained by the standard documents.

Reference will now be made in detail to the embodiments of the present disclosure with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure, rather than to show the only embodiments that can be implemented according to the disclosure.

The following detailed description includes specific terms in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the specific terms may be replaced with other terms without departing the technical spirit and scope of the present disclosure.

The embodiments of the present disclosure can be applied to various radio access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc.

Hereinafter, in order to clarify the following description, a description is made based on a 3GPP communication system (e.g., LTE, NR, etc.), but the technical spirit of the present disclosure is not limited thereto. LTE may refer to technology after 3GPP TS 36.xxx Release 8. In detail, LTE technology after 3GPP TS 36.xxx Release 10 may be referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 may be referred to as LTE-A pro. 3GPP NR may refer to technology after TS 38.xxx Release 15. 3GPP 6G may refer to technology TS Release 17 and/or Release 18. “xxx” may refer to a detailed number of a standard document. LTE/NR/6G may be collectively referred to as a 3GPP system.

For background arts, terms, abbreviations, etc. used in the present disclosure, refer to matters described in the standard documents published prior to the present disclosure. For example, reference may be made to the standard documents 36.xxx and 38.xxx.

Communication System Applicable to the Present Disclosure

Without being limited thereto, various descriptions, functions, procedures, proposals, methods and/or operational flowcharts of the present disclosure disclosed herein are applicable to various fields requiring wireless communication/connection (e.g., 5G).

Hereinafter, a more detailed description will be given with reference to the drawings. In the following drawings/description, the same reference numerals may exemplify the same or corresponding hardware blocks, software blocks or functional blocks unless indicated otherwise.

FIG. 1 is a view showing an example of a communication system applicable to the present disclosure.

Referring to FIG. 1 , the communication system 100 applicable to the present disclosure includes a wireless device, a base station and a network. The wireless device refers to a device for performing communication using radio access technology (e.g., 5G NR or LTE) and may be referred to as a communication/wireless/5G device. Without being limited thereto, the wireless device may include a robot 100 a, vehicles 100 b-1 and 100 b-2, an extended reality (XR) device 100 c, a hand-held device 100 d, a home appliance 100 e, an Internet of Thing (IoT) device 100 f, and an artificial intelligence (AI) device/server 100 g. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. The vehicles 100 b-1 and 100 b-2 may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device 100 c includes an augmented reality (AR)/virtual reality (VR)/mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle or a robot. The hand-held device 100 d may include a smartphone, a smart pad, a wearable device (e.g., a smart watch or smart glasses), a computer (e.g., a laptop), etc. The home appliance 100 e may include a TV, a refrigerator, a washing machine, etc. The IoT device 100 f may include a sensor, a smart meter, etc. For example, the base station 120 and the network 130 may be implemented by a wireless device, and a specific wireless device 120 a may operate as a base station/network node for another wireless device.

The wireless devices 100 a to 100 f may be connected to the network 130 through the base station 120. AI technology is applicable to the wireless devices 100 a to 100 f, and the wireless devices 100 a to 100 f may be connected to the AI server 100 g through the network 130. The network 130 may be configured using a 3G network, a 4G (e.g., LTE) network or a 5G (e.g., NR) network, etc. The wireless devices 100 a to 100 f may communicate with each other through the base station 120/the network 130 or perform direct communication (e.g., sidelink communication) without through the base station 120/the network 130. For example, the vehicles 100 b-1 and 100 b-2 may perform direct communication (e.g., vehicle to vehicle (V2V)/vehicle to everything (V2X) communication). In addition, the IoT device 100 f (e.g., a sensor) may perform direct communication with another IoT device (e.g., a sensor) or the other wireless devices 100 a to 100 f.

Wireless communications/connections 150 a, 150 b and 150 c may be established between the wireless devices 100 a to 100 f/the base station 120 and the base station 120/the base station 120. Here, wireless communication/connection may be established through various radio access technologies (e.g., 5G NR) such as uplink/downlink communication 150 a, sidelink communication 150 b (or D2D communication) or communication 150 c between base stations (e.g., relay, integrated access backhaul (IAB). The wireless device and the base station/wireless device or the base station and the base station may transmit/receive radio signals to/from each other through wireless communication/connection 150 a, 150 b and 150 c. For example, wireless communication/connection 150 a, 150 b and 150 c may enable signal transmission/reception through various physical channels. To this end, based on the various proposals of the present disclosure, at least some of various configuration information setting processes for transmission/reception of radio signals, various signal processing procedures (e.g., channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), resource allocation processes, etc. may be performed.

Wireless Device Applicable to the Present Disclosure

FIG. 2 is a view showing an example of a wireless device applicable to the present disclosure.

Referring to FIG. 2 , a first wireless device 200 a and a second wireless device 200 b may transmit and receive radio signals through various radio access technologies (e.g., LTE or NR). Here, {the first wireless device 200 a, the second wireless device 200 b} may correspond to {the wireless device 100 x, the base station 120} and/or {the wireless device 100 x, the wireless device 100 x} of FIG. 1 .

The first wireless device 200 a may include one or more processors 202 a and one or more memories 204 a and may further include one or more transceivers 206 a and/or one or more antennas 208 a. The processor 202 a may be configured to control the memory 204 a and/or the transceiver 206 a and to implement descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. For example, the processor 202 a may process information in the memory 204 a to generate first information/signal and then transmit a radio signal including the first information/signal through the transceiver 206 a. In addition, the processor 202 a may receive a radio signal including second information/signal through the transceiver 206 a and then store information obtained from signal processing of the second information/signal in the memory 204 a. The memory 204 a may be coupled with the processor 202 a, and store a variety of information related to operation of the processor 202 a. For example, the memory 204 a may store software code including instructions for performing all or some of the processes controlled by the processor 202 a or performing the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. Here, the processor 202 a and the memory 204 a may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE or NR). The transceiver 206 a may be coupled with the processor 202 a to transmit and/or receive radio signals through one or more antennas 208 a. The transceiver 206 a may include a transmitter and/or a receiver. The transceiver 206 a may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the wireless device may refer to a communication modem/circuit/chip.

For example, the first wireless device may include a wireless transceiver and a processor. The wireless transceiver may receive a first system information block (SIB) from a first base station, and the received first SIB may include at least one first parameter for a cell reselection learning model. The wireless transceiver may receive radio channel environment information from the first base station. The processor may update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information. A second base station may be reselected based on the updated at least one second parameter.

As another example, the first wireless device may include transceiver and a processor connected to the transceiver. The transceiver may receive parameter information related to a cell reselection learning model from a plurality of terminals. The processor may generate at least one first parameter for the cell reselection learning model based on the received parameter information. The transceiver may transmit a system information block (SIB) including the at least one first parameter to a first terminal. The transceiver may transmit radio channel environment information to the first terminal.

As another example, the first wireless device may include at least one memory and at least one processor functionally connected to the at least one memory. The at least one processor may control the first wireless device to receive a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The at least one processor may control the first wireless device to receive radio channel environment information from the first base station. The at least one processor may control the first wireless device to update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information. The at least one processor may control the first wireless device to perform cell reselection for a second base station based on the updated at least one second parameter.

The second wireless device 200 b may include one or more processors 202 b and one or more memories 204 b and may further include one or more transceivers 206 b and/or one or more antennas 208 b. The processor 202 b may be configured to control the memory 204 b and/or the transceiver 206 b and to implement the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. For example, the processor 202 b may process information in the memory 204 b to generate third information/signal and then transmit the third information/signal through the transceiver 206 b. In addition, the processor 202 b may receive a radio signal including fourth information/signal through the transceiver 206 b and then store information obtained from signal processing of the fourth information/signal in the memory 204 b. The memory 204 b may be coupled with the processor 202 b to store a variety of information related to operation of the processor 202 b. For example, the memory 204 b may store software code including instructions for performing all or some of the processes controlled by the processor 202 b or performing the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. Herein, the processor 202 b and the memory 204 b may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE or NR). The transceiver 206 b may be coupled with the processor 202 b to transmit and/or receive radio signals through one or more antennas 208 b. The transceiver 206 b may include a transmitter and/or a receiver. The transceiver 206 b may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the wireless device may refer to a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 200 a and 200 b will be described in greater detail. Without being limited thereto, one or more protocol layers may be implemented by one or more processors 202 a and 202 b. For example, one or more processors 202 a and 202 b may implement one or more layers (e.g., functional layers such as PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), SDAP (service data adaptation protocol)). One or more processors 202 a and 202 b may generate one or more protocol data units (PDUs) and/or one or more service data unit (SDU) according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. One or more processors 202 a and 202 b may generate messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. One or more processors 202 a and 202 b may generate PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed herein and provide the PDUs, SDUs, messages, control information, data or information to one or more transceivers 206 a and 206 b. One or more processors 202 a and 202 b may receive signals (e.g., baseband signals) from one or more transceivers 206 a and 206 b and acquire PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein.

One or more processors 202 a and 202 b may be referred to as controllers, microcontrollers, microprocessors or microcomputers. One or more processors 202 a and 202 b may be implemented by hardware, firmware, software or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), programmable logic devices (PLDs) or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 202 a and 202 b. The descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein may be implemented using firmware or software, and firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein may be included in one or more processors 202 a and 202 b or stored in one or more memories 204 a and 204 b to be driven by one or more processors 202 a and 202 b. The descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein implemented using firmware or software in the form of code, a command and/or a set of commands.

As an example, a first wireless device may be a non-transitory computer-readable medium storing at least one instruction. The computer-readable medium may comprise at least one instruction executable by a processor. The at least one instruction may instruct the computer-readable medium to receive a first system information block (SIB) from a first base station. The received first SIB may include at least one first parameter for a cell reselection learning model. The at least one instruction may instruct the computer-readable medium to receive radio channel environment information from the first base station. The at least one instruction may instruct the computer-readable medium to update the first parameter to a second parameter through learning in the cell reselection learning model by reflecting the radio channel environment information. The at least one instruction may instruct the computer-readable medium to perform cell reselection for a second base station based on the updated at least one second parameter.

One or more memories 204 a and 204 b may be coupled with one or more processors 202 a and 202 b to store various types of data, signals, messages, information, programs, code, instructions and/or commands. One or more memories 204 a and 204 b may be composed of read only memories (ROMs), random access memories (RAMs), erasable programmable read only memories (EPROMs), flash memories, hard drives, registers, cache memories, computer-readable storage mediums and/or combinations thereof. One or more memories 204 a and 204 b may be located inside and/or outside one or more processors 202 a and 202 b. In addition, one or more memories 204 a and 204 b may be coupled with one or more processors 202 a and 202 b through various technologies such as wired or wireless connection.

One or more transceivers 206 a and 206 b may transmit user data, control information, radio signals/channels, etc. described in the methods and/or operational flowcharts of the present disclosure to one or more other apparatuses. One or more transceivers 206 a and 206 b may receive user data, control information, radio signals/channels, etc. described in the methods and/or operational flowcharts of the present disclosure from one or more other apparatuses. For example, one or more transceivers 206 a and 206 b may be coupled with one or more processors 202 a and 202 b to transmit/receive radio signals. For example, one or more processors 202 a and 202 b may perform control such that one or more transceivers 206 a and 206 b transmit user data, control information or radio signals to one or more other apparatuses. In addition, one or more processors 202 a and 202 b may perform control such that one or more transceivers 206 a and 206 b receive user data, control information or radio signals from one or more other apparatuses. In addition, one or more transceivers 206 a and 206 b may be coupled with one or more antennas 208 a and 208 b, and one or more transceivers 206 a and 206 b may be configured to transmit/receive user data, control information, radio signals/channels, etc. described in the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein through one or more antennas 208 a and 208 b. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers 206 a and 206 b may convert the received radio signals/channels, etc. from RF band signals to baseband signals, in order to process the received user data, control information, radio signals/channels, etc. using one or more processors 202 a and 202 b. One or more transceivers 206 a and 206 b may convert the user data, control information, radio signals/channels processed using one or more processors 202 a and 202 b from baseband signals into RF band signals. To this end, one or more transceivers 206 a and 206 b may include (analog) oscillator and/or filters.

Structure of Wireless Device Applicable to the Present Disclosure

FIG. 3 is a view showing another example of a wireless device applicable to the present disclosure.

Referring to FIG. 3 , a wireless device 300 may correspond to the wireless devices 200 a and 200 b of FIG. 2 and include various elements, components, units/portions and/or modules. For example, the wireless device 300 may include a communication unit 310, a control unit (controller) 320, a memory unit (memory) 330 and additional components 340. The communication unit may include a communication circuit 312 and a transceiver(s) 314. For example, the communication circuit 312 may include one or more processors 202 a and 202 b and/or one or more memories 204 a and 204 b of FIG. 2 . For example, the transceiver(s) 314 may include one or more transceivers 206 a and 206 b and/or one or more antennas 208 a and 208 b of FIG. 2 . The control unit 320 may be electrically coupled with the communication unit 310, the memory unit 330 and the additional components 340 to control overall operation of the wireless device. For example, the control unit 320 may control electrical/mechanical operation of the wireless device based on a program/code/instruction/information stored in the memory unit 330. In addition, the control unit 320 may transmit the information stored in the memory unit 330 to the outside (e.g., another communication device) through the wireless/wired interface using the communication unit 310 over a wireless/wired interface or store information received from the outside (e.g., another communication device) through the wireless/wired interface using the communication unit 310 in the memory unit 330.

The additional components 340 may be variously configured according to the types of the wireless devices. For example, the additional components 340 may include at least one of a power unit/battery, an input/output unit, a driving unit or a computing unit. Without being limited thereto, the wireless device 300 may be implemented in the form of the robot (FIG. 1, 100 a), the vehicles (FIGS. 1, 100 b-1 and 100 b-2), the XR device (FIG. 1, 100 c), the hand-held device (FIG. 1, 100 d), the home appliance (FIG. 1, 100 e), the IoT device (FIG. 1, 1000 , a digital broadcast terminal, a hologram apparatus, a public safety apparatus, an MTC apparatus, a medical apparatus, a Fintech device (financial device), a security device, a climate/environment device, an AI server/device (FIG. 1, 140 ), the base station (FIG. 1, 120 ), a network node, etc. The wireless device may be movable or may be used at a fixed place according to use example/service.

In FIG. 3 , various elements, components, units/portions and/or modules in the wireless device 300 may be coupled with each other through wired interfaces or at least some thereof may be wirelessly coupled through the communication unit 310. For example, in the wireless device 300, the control unit 320 and the communication unit 310 may be coupled by wire, and the control unit 320 and the first unit (e.g., 130 or 140) may be wirelessly coupled through the communication unit 310. In addition, each element, component, unit/portion and/or module of the wireless device 300 may further include one or more elements. For example, the control unit 320 may be composed of a set of one or more processors. For example, the control unit 320 may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphic processing processor, a memory control processor, etc. In another example, the memory unit 330 may be composed of a random access memory (RAM), a dynamic RAM (DRAM), a read only memory (ROM), a flash memory, a volatile memory, a non-volatile memory and/or a combination thereof

Hand-held Device Applicable to the Present Disclosure

FIG. 4 is a view showing an example of a hand-held device applicable to the present disclosure.

FIG. 4 shows a hand-held device applicable to the present disclosure. The hand-held device may include a smartphone, a smart pad, a wearable device (e.g., a smart watch or smart glasses), and a hand-held computer (e.g., a laptop, etc.). The hand-held device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS) or a wireless terminal (WT).

Referring to FIG. 4 , the hand-held device 400 may include an antenna unit (antenna) 408, a communication unit (transceiver) 410, a control unit (controller) 420, a memory unit (memory) 430, a power supply unit (power supply) 440 a, an interface unit (interface) 440 b, and an input/output unit 440 c. An antenna unit (antenna) 408 may be part of the communication unit 410. The blocks 410 to 430/440 a to 440 c may correspond to the blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 410 may transmit and receive signals (e.g., data, control signals, etc.) to and from other wireless devices or base stations. The control unit 420 may control the components of the hand-held device 400 to perform various operations. The control unit 420 may include an application processor (AP). The memory unit 430 may store data/parameters/program/code/instructions necessary to drive the hand-held device 400. In addition, the memory unit 430 may store input/output data/information, etc. The power supply unit 440 a may supply power to the hand-held device 400 and include a wired/wireless charging circuit, a battery, etc. The interface unit 440 b may support connection between the hand-held device 400 and another external device. The interface unit 440 b may include various ports (e.g., an audio input/output port and a video input/output port) for connection with the external device. The input/output unit 440 c may receive or output video information/signals, audio information/signals, data and/or user input information. The input/output unit 440 c may include a camera, a microphone, a user input unit, a display 440 d, a speaker and/or a haptic module.

For example, in case of data communication, the input/output unit 440 c may acquire user input information/signal (e.g., touch, text, voice, image or video) from the user and store the user input information/signal in the memory unit 430. The communication unit 410 may convert the information/signal stored in the memory into a radio signal and transmit the converted radio signal to another wireless device directly or transmit the converted radio signal to a base station. In addition, the communication unit 410 may receive a radio signal from another wireless device or the base station and then restore the received radio signal into original information/signal. The restored information/signal may be stored in the memory unit 430 and then output through the input/output unit 440 c in various forms (e.g., text, voice, image, video and haptic).

Type of Wireless Device Applicable to the Present Disclosure

FIG. 5 is a view showing an example of a car or an autonomous driving car applicable to the present disclosure.

FIG. 5 shows a car or an autonomous driving vehicle applicable to the present disclosure. The car or the autonomous driving car may be implemented as a mobile robot, a vehicle, a train, a manned/unmanned aerial vehicle (AV), a ship, etc. and the type of the car is not limited.

Referring to FIG. 5 , the car or autonomous driving car 500 may include an antenna unit (antenna) 508, a communication unit (transceiver) 510, a control unit (controller) 520, a driving unit 540 a, a power supply unit (power supply) 540 b, a sensor unit 540 c, and an autonomous driving unit 540 d. The antenna unit 550 may be configured as part of the communication unit 510. The blocks 510/530/540 a to 540 d correspond to the blocks 410/430/440 of FIG. 4 .

The communication unit 510 may transmit and receive signals (e.g., data, control signals, etc.) to and from external devices such as another vehicle, a base station (e.g., a base station, a road side unit, etc.), and a server. The control unit 520 may control the elements of the car or autonomous driving car 500 to perform various operations. The control unit 520 may include an electronic control unit (ECU). The driving unit 540 a may drive the car or autonomous driving car 500 on the ground. The driving unit 540 a may include an engine, a motor, a power train, wheels, a brake, a steering device, etc. The power supply unit 540 b may supply power to the car or autonomous driving car 500, and include a wired/wireless charging circuit, a battery, etc. The sensor unit 540 c may obtain a vehicle state, surrounding environment information, user information, etc. The sensor unit 540 c may include an inertial navigation unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a brake pedal position sensor, and so on. The autonomous driving sensor 540 d may implement technology for maintaining a driving lane, technology for automatically controlling a speed such as adaptive cruise control, technology for automatically driving the car along a predetermined route, technology for automatically setting a route when a destination is set and driving the car, etc.

For example, the communication unit 510 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 540 d may generate an autonomous driving route and a driving plan based on the acquired data. The control unit 520 may control the driving unit 540 a (e.g., speed/direction control) such that the car or autonomous driving car 500 moves along the autonomous driving route according to the driving plane. During autonomous driving, the communication unit 510 may aperiodically/periodically acquire latest traffic information data from an external server and acquire surrounding traffic information data from neighboring cars. In addition, during autonomous driving, the sensor unit 540 c may acquire a vehicle state and surrounding environment information. The autonomous driving unit 540 d may update the autonomous driving route and the driving plan based on newly acquired data/information. The communication unit 510 may transmit information such as a vehicle location, an autonomous driving route, a driving plan, etc. to the external server. The external server may predict traffic information data using AI technology or the like based on the information collected from the cars or autonomous driving cars and provide the predicted traffic information data to the cars or autonomous driving cars.

FIG. 6 is a view showing an example of a mobility applicable to the present disclosure.

Referring to FIG. 6 , the mobility applied to the present disclosure may be implemented as at least one of a transportation means, a train, an aerial vehicle or a ship. In addition, the mobility applied to the present disclosure may be implemented in the other forms and is not limited to the above-described embodiments.

At this time, referring to FIG. 6 , the mobility 600 may include a communication unit (transceiver) 610, a control unit (controller) 620, a memory unit (memory) 630, an input/output unit 640 a and a positioning unit 640 b. Here, the blocks 610 to 630/640 a to 640 b may corresponding to the blocks 310 to 330/340 of FIG. 3 .

The communication unit 610 may transmit and receive signals (e.g., data, control signals, etc.) to and from external devices such as another mobility or a base station. The control unit 620 may control the components of the mobility 600 to perform various operations. The memory unit 630 may store data/parameters/programs/code/instructions supporting the various functions of the mobility 600. The input/output unit 640 a may output AR/VR objects based on information in the memory unit 630. The input/output unit 640 a may include a HUD. The positioning unit 640 b may acquire the position information of the mobility 600. The position information may include absolute position information of the mobility 600, position information in a driving line, acceleration information, position information of neighboring vehicles, etc. The positioning unit 640 b may include a global positioning system (GPS) and various sensors.

For example, the communication unit 610 of the mobility 600 may receive map information, traffic information, etc. from an external server and store the map information, the traffic information, etc. in the memory unit 630. The positioning unit 640 b may acquire mobility position information through the GPS and the various sensors and store the mobility position information in the memory unit 630. The control unit 620 may generate a virtual object based on the map information, the traffic information, the mobility position information, etc., and the input/output unit 640 a may display the generated virtual object in a glass window (651 and 652). In addition, the control unit 620 may determine whether the mobility 600 is normally driven in the driving line based on the mobility position information. When the mobility 600 abnormally deviates from the driving line, the control unit 620 may display a warning on the glass window of the mobility through the input/output unit 640 a. In addition, the control unit 620 may broadcast a warning message for driving abnormality to neighboring mobilities through the communication unit 610. Depending on situations, the control unit 620 may transmit the position information of the mobility and information on driving/mobility abnormality to a related institution through the communication unit 610.

FIG. 7 is a view showing an example of an XR device applicable to the present disclosure. The XR device may be implemented as a HMD, a head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc.

Referring to FIG. 7 , the XR device 700 a may include a communication unit (transceiver) 710, a control unit (controller) 720, a memory unit (memory) 730, an input/output unit 740 a, a sensor unit 740 b and a power supply unit (power supply) 740 c. Here, the blocks 710 to 730/740 a to 740 c may correspond to the blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 710 may transmit and receive signals (e.g., media data, control signals, etc.) to and from external devices such as another wireless device, a hand-held device or a media server. The media data may include video, image, sound, etc. The control unit 720 may control the components of the XR device 700 a to perform various operations. For example, the control unit 720 may be configured to control and/or perform procedures such as video/image acquisition, (video/image) encoding, metadata generation and processing. The memory unit 730 may store data/parameters/programs/code/instructions necessary to drive the XR device 700 a or generate an XR object.

The input/output unit 740 a may acquire control information, data, etc. from the outside and output the generated XR object. The input/output unit 740 a may include a camera, a microphone, a user input unit, a display, a speaker and/or a haptic module. The sensor unit 740 b may obtain an XR device state, surrounding environment information, user information, etc. The sensor unit 740 b may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertia sensor, a red green blue (RGB) sensor, an infrared (IR) sensor, a finger scan sensor, an ultrasonic sensor, an optical sensor, a microphone and/or a radar. The power supply unit 740 c may supply power to the XR device 700 a and include a wired/wireless charging circuit, a battery, etc.

For example, the memory unit 730 of the XR device 700 a may include information (e.g., data, etc.) necessary to generate an XR object (e.g., AR/VR/MR object). The input/output unit 740 a may acquire an instruction for manipulating the XR device 700 a from a user, and the control unit 720 may drive the XR device 700 a according to the driving instruction of the user. For example, when the user wants to watch a movie, news, etc. through the XR device 700 a, the control unit 720 may transmit content request information to another device (e.g., a hand-held device 700 b) or a media server through the communication unit 730. The communication unit 730 may download/stream content such as a movie or news from another device (e.g., the hand-held device 700 b) or the media server to the memory unit 730. The control unit 720 may control and/or perform procedures such as video/image acquisition, (video/image) encoding, metadata generation/processing, etc. with respect to content, and generate/output an XR object based on information on a surrounding space or a real object acquired through the input/output unit 740 a or the sensor unit 740 b.

In addition, the XR device 700 a may be wirelessly connected with the hand-held device 700 b through the communication unit 710, and operation of the XR device 700 a may be controlled by the hand-held device 700 b. For example, the hand-held device 700 b may operate as a controller for the XR device 700 a. To this end, the XR device 700 a may acquire three-dimensional position information of the hand-held device 700 b and then generate and output an XR object corresponding to the hand-held device 700 b.

FIG. 8 is a view showing an example of a robot applicable to the present disclosure. For example, the robot may be classified into industrial, medical, household, military, etc. according to the purpose or field of use. At this time, referring to FIG. 8 , the robot 800 may include a communication unit (transceiver) 810, a control unit (controller) 820, a memory unit (memory) 830, an input/output unit 840 a, sensor unit 840 b and a driving unit 840 c. Here, blocks 810 to 830/840 a to 840 c may correspond to the blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 810 may transmit and receive signals (e.g., driving information, control signals, etc.) to and from external devices such as another wireless device, another robot or a control server. The control unit 820 may control the components of the robot 800 to perform various operations. The memory unit 830 may store data/parameters/programs/code/instructions supporting various functions of the robot 800. The input/output unit 840 a may acquire information from the outside of the robot 800 and output information to the outside of the robot 800. The input/output unit 840 a may include a camera, a microphone, a user input unit, a display, a speaker and/or a haptic module.

The sensor unit 840 b may obtain internal information, surrounding environment information, user information, etc. of the robot 800. The sensor unit 840 b may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertia sensor, an infrared (IR) sensor, a finger scan sensor, an ultrasonic sensor, an optical sensor, a microphone and/or a radar.

The driving unit 840 c may perform various physical operations such as movement of robot joints. In addition, the driving unit 840 c may cause the robot 800 to run on the ground or fly in the air. The driving unit 840 c may include an actuator, a motor, wheels, a brake, a propeller, etc.

FIG. 9 is a view showing an example of artificial intelligence (AI) device applicable to the present disclosure. For example, the AI device may be implemented as fixed or movable devices such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcast terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, or the like.

Referring to FIG. 9 , the AI device 900 may include a communication unit (transceiver) 910, a control unit (controller) 920, a memory unit (memory) 930, an input/output unit 940 a/940 b, a leaning processor unit (learning processor) 940 c and a sensor unit 940 d. The blocks 910 to 930/940 a to 940 d may correspond to the blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 910 may transmit and receive wired/wireless signals (e.g., sensor information, user input, learning models, control signals, etc.) to and from external devices such as another AI device (e.g., FIG. 1, 100 x, 120 or 140) or the AI server (FIG. 1, 140 ) using wired/wireless communication technology. To this end, the communication unit 910 may transmit information in the memory unit 930 to an external device or transfer a signal received from the external device to the memory unit 930.

The control unit 920 may determine at least one executable operation of the AI device 900 based on information determined or generated using a data analysis algorithm or a machine learning algorithm. In addition, the control unit 920 may control the components of the AI device 900 to perform the determined operation. For example, the control unit 920 may request, search for, receive or utilize the data of the learning processor unit 940 c or the memory unit 930, and control the components of the AI device 900 to perform predicted operation or operation, which is determined to be desirable, of at least one executable operation. In addition, the control unit 920 may collect history information including operation of the AI device 900 or user's feedback on the operation and store the history information in the memory unit 930 or the learning processor unit 940 c or transmit the history information to the AI server (FIG. 1, 140 ). The collected history information may be used to update a learning model.

The memory unit 930 may store data supporting various functions of the AI device 900. For example, the memory unit 930 may store data obtained from the input unit 940 a, data obtained from the communication unit 910, output data of the learning processor unit 940 c, and data obtained from the sensing unit 940. In addition, the memory unit 930 may store control information and/or software code necessary to operate/execute the control unit 920.

The input unit 940 a may acquire various types of data from the outside of the AI device 900. For example, the input unit 940 a may acquire learning data for model learning, input data, to which the learning model will be applied, etc. The input unit 940 a may include a camera, a microphone and/or a user input unit. The output unit 940 b may generate video, audio or tactile output. The output unit 940 b may include a display, a speaker and/or a haptic module. The sensing unit 940 may obtain at least one of internal information of the AI device 900, the surrounding environment information of the AI device 900 and user information using various sensors. The sensing unit 940 may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertia sensor, a red green blue (RGB) sensor, an infrared (IR) sensor, a finger scan sensor, an ultrasonic sensor, an optical sensor, a microphone and/or a radar.

The learning processor unit 940 c may train a model composed of an artificial neural network using training data. The learning processor unit 940 c may perform AI processing along with the learning processor unit of the AI server (FIG. 1, 140 ). The learning processor unit 940 c may process information received from an external device through the communication unit 910 and/or information stored in the memory unit 930. In addition, the output value of the learning processor unit 940 c may be transmitted to the external device through the communication unit 910 and/or stored in the memory unit 930.

Physical Channels and General Signal Transmission

In a radio access system, a UE receives information from a base station on a DL and transmits information to the base station on a UL. The information transmitted and received between the UE and the base station includes general data information and a variety of control information. There are many physical channels according to the types/usages of information transmitted and received between the base station and the UE.

FIG. 10 is a view showing physical channels applicable to the present disclosure and a signal transmission method using the same.

The UE which is turned on again in a state of being turned off or has newly entered a cell performs initial cell search operation in step S1011 such as acquisition of synchronization with a base station. Specifically, the UE performs synchronization with the base station, by receiving a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station, and acquires information such as a cell Identifier (ID).

Thereafter, the UE may receive a physical broadcast channel (PBCH) signal from the base station and acquire intra-cell broadcast information. Meanwhile, the UE may receive a downlink reference signal (DL RS) in an initial cell search step and check a downlink channel state. The UE which has completed initial cell search may receive a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to physical downlink control channel information in step S1012, thereby acquiring more detailed system information.

Thereafter, the UE may perform a random access procedure such as steps S1013 to S1016 in order to complete access to the base station. To this end, the UE may transmit a preamble through a physical random access channel (PRACH) (S1013) and receive a random access response (RAR) to the preamble through a physical downlink control channel and a physical downlink shared channel corresponding thereto (S1014). The UE may transmit a physical uplink shared channel (PUSCH) using scheduling information in the RAR (S1015) and perform a contention resolution procedure such as reception of a physical downlink control channel signal and a physical downlink shared channel signal corresponding thereto (S1016).

The UE, which has performed the above-described procedures, may perform reception of a physical downlink control channel signal and/or a physical downlink shared channel signal (S1017) and transmission of a physical uplink shared channel (PUSCH) signal and/or a physical uplink control channel (PUCCH) signal (S1018) as general uplink/downlink signal transmission procedures.

The control information transmitted from the UE to the base station is collectively referred to as uplink control information (UCI). The UCI includes hybrid automatic repeat and request acknowledgement/negative-ACK (HARQ-ACK/NACK), scheduling request (SR), channel quality indication (CQI), precoding matrix indication (PMI), rank indication (RI), beam indication (BI) information, etc. At this time, the UCI is generally periodically transmitted through a PUCCH, but may be transmitted through a PUSCH in some embodiments (e.g., when control information and traffic data are simultaneously transmitted). In addition, the UE may aperiodically transmit UCI through a PUSCH according to a request/instruction of a network.

FIG. 11 is a view showing the structure of a control plane and a user plane of a radio interface protocol applicable to the present disclosure.

Referring to FIG. 11 , Entity 1 may be a user equipment (UE). At this time, the UE may be at least one of a wireless device, a hand-held device, a vehicle, a mobility, an XR device, a robot or an AI device, to which the present disclosure is applicable in FIGS. 1 to 9 . In addition, the UE refers to a device, to which the present disclosure is applicable, and is not limited to a specific apparatus or device.

Entity 2 may be a base station. At this time, the base station may be at least one of an eNB, a gNB or an ng-eNB. In addition, the base station may refer to a device for transmitting a downlink signal to a UE and is not limited to a specific apparatus or device. That is, the base station may be implemented in various forms or types and is not limited to a specific form.

Entity 3 may be a device for performing a network apparatus or a network function. At this time, the network apparatus may be a core network node (e.g., mobility management entity (MME) for managing mobility, an access and mobility management function (AMF), etc. In addition, the network function may mean a function implemented in order to perform a network function. Entity 3 may be a device, to which a function is applied. That is, Entity 3 may refer to a function or device for performing a network function and is not limited to a specific device.

A control plane refers to a path used for transmission of control messages, which are used by the UE and the network to manage a call. A user plane refers to a path in which data generated in an application layer, e.g. voice data or Internet packet data, is transmitted. At this time, a physical layer which is a first layer provides an information transfer service to a higher layer using a physical channel. The physical layer is connected to a media access control (MAC) layer of a higher layer via a transmission channel. At this time, data is transmitted between the MAC layer and the physical layer via the transmission channel. Data is also transmitted between a physical layer of a transmitter and a physical layer of a receiver via a physical channel. The physical channel uses time and frequency as radio resources.

The MAC layer which is a second layer provides a service to a radio link control (RLC) layer of a higher layer via a logical channel. The RLC layer of the second layer supports reliable data transmission. The function of the RLC layer may be implemented by a functional block within the MAC layer. A packet data convergence protocol (PDCP) layer which is the second layer performs a header compression function to reduce unnecessary control information for efficient transmission of an Internet protocol (IP) packet such as an IPv4 or IPv6 packet in a radio interface having relatively narrow bandwidth. A radio resource control (RRC) layer located at the bottommost portion of a third layer is defined only in the control plane. The RRC layer serves to control logical channels, transmission channels, and physical channels in relation to configuration, re-configuration, and release of radio bearers. A radio bearer (RB) refers to a service provided by the second layer to transmit data between the UE and the network. To this end, the RRC layer of the UE and the RRC layer of the network exchange RRC messages. A non-access stratum (NAS) layer located at a higher level of the RRC layer performs functions such as session management and mobility management. One cell configuring a base station may be set to one of various bandwidths to provide a downlink or uplink transmission service to several UEs. Different cells may be set to provide different bandwidths. Downlink transmission channels for transmitting data from a network to a UE may include a broadcast channel (BCH) for transmitting system information, a paging channel (PCH) for transmitting paging messages, and a DL shared channel (SCH) for transmitting user traffic or control messages. Traffic or control messages of a DL multicast or broadcast service may be transmitted through the DL SCH or may be transmitted through an additional DL multicast channel (MCH). Meanwhile, UL transmission channels for data transmission from the UE to the network include a random access channel (RACH) for transmitting initial control messages and a UL SCH for transmitting user traffic or control messages. Logical channels, which are located at a higher level of the transmission channels and are mapped to the transmission channels, include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and a multicast traffic channel (MTCH).

FIG. 12 is a view showing a method of processing a transmitted signal applicable to the present disclosure. For example, the transmitted signal may be processed by a signal processing circuit. At this time, a signal processing circuit 1200 may include a scrambler 1210, a modulator 1220, a layer mapper 1230, a precoder 1240, a resource mapper 1250, and a signal generator 1260. At this time, for example, the operation/function of FIG. 12 may be performed by the processors 202 a and 202 b and/or the transceiver 206 a and 206 b of FIG. 2 . In addition, for example, the hardware element of FIG. 12 may be implemented in the processors 202 a and 202 b of FIG. 2 and/or the transceivers 206 a and 206 b of FIG. 2 . For example, blocks 1010 to 1060 may be implemented in the processors 202 a and 202 b of FIG. 2 . In addition, blocks 1210 to 1250 may be implemented in the processors 202 a and 202 b of FIG. 2 and a block 1260 may be implemented in the transceivers 206 a and 206 b of FIG. 2 , without being limited to the above-described embodiments.

A codeword may be converted into a radio signal through the signal processing circuit 1200 of FIG. 12 . Here, the codeword is a coded bit sequence of an information block. The information block may include a transport block (e.g., a UL-SCH transport block or a DL-SCH transport block). The radio signal may be transmitted through various physical channels (e.g., a PUSCH and a PDSCH) of FIG. 10 . Specifically, the codeword may be converted into a bit sequence scrambled by the scrambler 1210. The scramble sequence used for scramble is generated based in an initial value and the initial value may include ID information of a wireless device, etc. The scrambled bit sequence may be modulated into a modulated symbol sequence by the modulator 1220. The modulation method may include pi/2-binary phase shift keying (pi/2-BPSK), m-phase shift keying (m-PSK), m-quadrature amplitude modulation (m-QAM), etc.

A complex modulation symbol sequence may be mapped to one or more transport layer by the layer mapper 1230. Modulation symbols of each transport layer may be mapped to corresponding antenna port(s) by the precoder 1240 (precoding). The output z of the precoder 1240 may be obtained by multiplying the output y of the layer mapper 1230 by an N*M precoding matrix W. Here, N may be the number of antenna ports and M may be the number of transport layers. Here, the precoder 1240 may perform precoding after transform precoding (e.g., discrete Fourier transform (DFT)) for complex modulation symbols. In addition, the precoder 1240 may perform precoding without performing transform precoding.

The resource mapper 1250 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include a plurality of symbols (e.g., a CP-OFDMA symbol and a DFT-s-OFDMA symbol) in the time domain and include a plurality of subcarriers in the frequency domain. The signal generator 1260 may generate a radio signal from the mapped modulation symbols, and the generated radio signal may be transmitted to another device through each antenna. To this end, the signal generator 1260 may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) insertor, a digital-to-analog converter (DAC), a frequency uplink converter, etc.

A signal processing procedure for a received signal in the wireless device may be configured as the inverse of the signal processing procedures 1210 to 1260 of FIG. 12 . For example, the wireless device (e.g., 200 a or 200 b of FIG. 2 ) may receive a radio signal from the outside through an antenna port/transceiver. The received radio signal may be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource de-mapper process, a postcoding process, a demodulation process and a de-scrambling process. The codeword may be restored to an original information block through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler and a decoder.

FIG. 13 is a view showing the structure of a radio frame applicable to the present disclosure.

UL and DL transmission based on an NR system may be based on the frame shown in FIG. 13 . At this time, one radio frame has a length of 10 ms and may be defined as two 5-ms half-frames (HFs). One half-frame may be defined as five 1-ms subframes (SFs). One subframe may be divided into one or more slots and the number of slots in the subframe may depend on subscriber spacing (SCS). At this time, each slot may include 12 or 14 OFDM(A) symbols according to cyclic prefix (CP). If normal CP is used, each slot may include 14 symbols. If an extended CP is used, each slot may include 12 symbols. Here, the symbol may include an OFDM symbol (or a CP-OFDM symbol) and an SC-FDMA symbol (or a DFT-s-OFDM symbol).

Table 1 shows the number of symbols per slot according to SCS, the number of slots per frame and the number of slots per subframe when normal CP is used, and Table 2 shows the number of symbols per slot according to SCS, the number of slots per frame and the number of slots per subframe when extended CP is used.

TABLE 1 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ) 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16 5 14 320 32

TABLE 2 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ) 2 12 40 4

In Tables 1 and 2 above, Nslotsymb may indicate the number of symbols in a slot, Nframe,μslot may indicate the number of slots in a frame, and Nsubframe,μslot may indicate the number of slots in a subframe.

In addition, in a system, to which the present disclosure is applicable, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be differently set among a plurality of cells merged to one UE. Accordingly, an (absolute time) period of a time resource (e.g., an SF, a slot or a TTI) (for convenience, collectively referred to as a time unit (TU)) composed of the same number of symbols may be differently set between merged cells.

NR may support a plurality of numerologies (or subscriber spacings (SCSs)) supporting various 5G services. For example, a wide area in traditional cellular bands is supported when the SCS is 15 kHz, dense-urban, lower latency and wider carrier bandwidth are supported when the SCS is 30 kHz/60 kHz, and bandwidth greater than 24.25 GHz may be supported to overcome phase noise when the SCS is 60 kHz or higher.

An NR frequency band is defined as two types (FR1 and FR2) of frequency ranges. FR1 and FR2 may be configured as shown in the following table. In addition, FR2 may mean millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding Subcarrier designation frequency range Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz

In addition, for example, in a communication system, to which the present disclosure is applicable, the above-described numerology may be differently set. For example, a terahertz wave (THz) band may be used as a frequency band higher than FR2. In the THz band, the SCS may be set greater than that of the NR system, and the number of slots may be differently set, without being limited to the above-described embodiments. The THz band will be described below.

FIG. 14 is a view showing a slot structure applicable to the present disclosure.

One slot includes a plurality of symbols in the time domain. For example, one slot includes seven symbols in case of normal CP and one slot includes six symbols in case of extended CP. A carrier includes a plurality of subcarriers in the frequency domain. A resource block (RB) may be defined as a plurality (e.g., 12) of consecutive subcarriers in the frequency domain.

In addition, a bandwidth part (BWP) is defined as a plurality of consecutive (P)RBs in the frequency domain and may correspond to one numerology (e.g., SCS, CP length, etc.).

The carrier may include a maximum of N (e.g., five) BWPs. Data communication is performed through an activated BWP and only one BWP may be activated for one UE. In resource grid, each element is referred to as a resource element (RE) and one complex symbol may be mapped.

6G communication System

A 6G (wireless communication) system has purposes such as (i) very high data rate per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) decrease in energy consumption of battery-free IoT devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capacity. The vision of the 6G system may include four aspects such as “intelligent connectivity”, “deep connectivity”, “holographic connectivity” and “ubiquitous connectivity”, and the 6G system may satisfy the requirements shown in Table 4 below. That is, Table 4 shows the requirements of the 6G system.

TABLE 4 Per device peak data rate 1 Tbps E2E latency 1 ms Maximum spectral efficiency 100 bps/Hz Mobility support Up to 1000 km/hr Satellite integration Fully AI Fully Autonomous vehicle Fully XR Fully Haptic Communication Fully

At this time, the 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine type communications (mMTC), AI integrated communication, tactile Internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion and enhanced data security.

FIG. 15 is a view showing an example of a communication structure providable in a 6G system applicable to the present disclosure.

Referring to FIG. 15 , the 6G system will have 50 times higher simultaneous wireless communication connectivity than a 5G wireless communication system. URLLC, which is the key feature of 5G, will become more important technology by providing end-to-end latency less than 1 ms in 6G communication. At this time, the 6G system may have much better volumetric spectrum efficiency unlike frequently used domain spectrum efficiency. The 6G system may provide advanced battery technology for energy harvesting and very long battery life and thus mobile devices may not need to be separately charged in the 6G system. In addition, in 6G, new network characteristics may be as follows.

-   -   Satellites integrated network: To provide a global mobile group,         6G will be integrated with satellite. Integrating terrestrial         waves, satellites and public networks as one wireless         communication system may be very important for 6G.     -   Connected intelligence: Unlike the wireless communication         systems of previous generations, 6G is innovative and wireless         evolution may be updated from “connected things” to “connected         intelligence”. AI may be applied in each step (or each signal         processing procedure which will be described below) of a         communication procedure.     -   Seamless integration of wireless information and energy         transfer: A 6G wireless network may transfer power in order to         charge the batteries of devices such as smartphones and sensors.         Therefore, wireless information and energy transfer (WIET) will         be integrated.     -   Ubiquitous super 3-dimemtion connectivity: Access to networks         and core network functions of drones and very low earth orbit         satellites will establish super 3D connection in 6G ubiquitous.

In the new network characteristics of 6G, several general requirements may be as follows.

-   -   Small cell networks: The idea of a small cell network was         introduced in order to improve received signal quality as a         result of throughput, energy efficiency and spectrum efficiency         improvement in a cellular system. As a result, the small cell         network is an essential feature for 5G and beyond 5G (5GB)         communication systems. Accordingly, the 6G communication system         also employs the characteristics of the small cell network.     -   Ultra-dense heterogeneous network: Ultra-dense heterogeneous         networks will be another important characteristic of the 6G         communication system. A multi-tier network composed of         heterogeneous networks improves overall QoS and reduces costs.     -   High-capacity backhaul: Backhaul connection is characterized by         a high-capacity backhaul network in order to support         high-capacity traffic. A high-speed optical fiber and free space         optical (FSO) system may be a possible solution for this         problem.     -   Radar technology integrated with mobile technology:         High-precision localization (or location-based service) through         communication is one of the functions of the 6G wireless         communication system. Accordingly, the radar system will be         integrated with the 6G network.     -   Softwarization and virtualization: Softwarization and         virtualization are two important functions which are the bases         of a design process in a 5GB network in order to ensure         flexibility, reconfigurability and programmability.

Core Implementation Technology of 6G System

-   -   Artificial Intelligence (AI)

Technology which is most important in the 6G system and will be newly introduced is AI. AI was not involved in the 4G system. A 5G system will support partial or very limited AI. However, the 6G system will support AI for full automation. Advance in machine learning will create a more intelligent network for real-time communication in 6G. When AI is introduced to communication, real-time data transmission may be simplified and improved. AI may determine a method of performing complicated target tasks using countless analysis. That is, AI may increase efficiency and reduce processing delay.

Time-consuming tasks such as handover, network selection or resource scheduling may be immediately performed by using AI. AI may play an important role even in M2M, machine-to-human and human-to-machine communication. In addition, AI may be rapid communication in a brain computer interface (BCI). An AI based communication system may be supported by meta materials, intelligent structures, intelligent networks, intelligent devices, intelligent recognition radios, self-maintaining wireless networks and machine learning.

Recently, attempts have been made to integrate AI with a wireless communication system in the application layer or the network layer, but deep learning have been focused on the wireless resource management and allocation field. However, such studies are gradually developed to the MAC layer and the physical layer, and, particularly, attempts to combine deep learning in the physical layer with wireless transmission are emerging. AI-based physical layer transmission means applying a signal processing and communication mechanism based on an AI driver rather than a traditional communication framework in a fundamental signal processing and communication mechanism. For example, channel coding and decoding based on deep learning, signal estimation and detection based on deep learning, multiple input multiple output (MIMO) mechanisms based on deep learning, resource scheduling and allocation based on AI, etc. may be included.

Machine learning may be used for channel estimation and channel tracking and may be used for power allocation, interference cancellation, etc. in the physical layer of DL. In addition, machine learning may be used for antenna selection, power control, symbol detection, etc. in the MIMO system.

However, application of a deep neutral network (DNN) for transmission in the physical layer may have the following problems.

Deep learning-based AI algorithms require a lot of training data in order to optimize training parameters. However, due to limitations in acquiring data in a specific channel environment as training data, a lot of training data is used offline. Static training for training data in a specific channel environment may cause a contradiction between the diversity and dynamic characteristics of a radio channel.

In addition, currently, deep learning mainly targets real signals. However, the signals of the physical layer of wireless communication are complex signals. For matching of the characteristics of a wireless communication signal, studies on a neural network for detecting a complex domain signal are further required.

Hereinafter, machine learning will be described in greater detail.

Machine learning refers to a series of operations to train a machine in order to build a machine which can perform tasks which cannot be performed or are difficult to be performed by people. Machine learning requires data and learning models. In machine learning, data learning methods may be roughly divided into three methods, that is, supervised learning, unsupervised learning and reinforcement learning.

Neural network learning is to minimize output error. Neural network learning refers to a process of repeatedly inputting training data to a neural network, calculating the error of the output and target of the neural network for the training data, backpropagating the error of the neural network from the output layer of the neural network to an input layer in order to reduce the error and updating the weight of each node of the neural network.

Supervised learning may use training data labeled with a correct answer and the unsupervised learning may use training data which is not labeled with a correct answer. That is, for example, in case of supervised learning for data classification, training data may be labeled with a category. The labeled training data may be input to the neural network, and the output (category) of the neural network may be compared with the label of the training data, thereby calculating the error. The calculated error is backpropagated from the neural network backward (that is, from the output layer to the input layer), and the connection weight of each node of each layer of the neural network may be updated according to backpropagation. Change in updated connection weight of each node may be determined according to the learning rate. Calculation of the neural network for input data and backpropagation of the error may configure a learning cycle (epoch). The learning data is differently applicable according to the number of repetitions of the learning cycle of the neural network. For example, in the early phase of learning of the neural network, a high learning rate may be used to increase efficiency such that the neural network rapidly ensures a certain level of performance and, in the late phase of learning, a low learning rate may be used to increase accuracy.

The learning method may vary according to the feature of data. For example, for the purpose of accurately predicting data transmitted from a transmitter in a receiver in a communication system, learning may be performed using supervised learning rather than unsupervised learning or reinforcement learning.

The learning model corresponds to the human brain and may be regarded as the most basic linear model. However, a paradigm of machine learning using a neural network structure having high complexity, such as artificial neural networks, as a learning model is referred to as deep learning.

Neural network cores used as a learning method may roughly include a deep neural network (DNN) method, a convolutional deep neural network (CNN) method and a recurrent Boltzmman machine (RNN) method. Such a learning model is applicable.

Terahertz (THz) Communication

THz communication is applicable to the 6G system. For example, a data rate may increase by increasing bandwidth. This may be performed by using sub-THz communication with wide bandwidth and applying advanced massive MIMO technology.

FIG. 16 is a view showing an electromagnetic spectrum applicable to the present disclosure. For example, referring to FIG. 16 , THz waves which are known as sub-millimeter radiation, generally indicates a frequency band between 0.1 THz and 10 THz with a corresponding wavelength in a range of 0.03 mm to 3 mm. A band range of 100 GHz to 300 GHz (sub THz band) is regarded as a main part of the THz band for cellular communication. When the sub-THz band is added to the mmWave band, the 6G cellular communication capacity increases. 300 GHz to 3 THz of the defined THz band is in a far infrared (IR) frequency band. A band of 300 GHz to 3 THz is a part of an optical band but is at the border of the optical band and is just behind an RF band. Accordingly, the band of 300 GHz to 3 THz has similarity with RF.

The main characteristics of THz communication include (i) bandwidth widely available to support a very high data rate and (ii) high path loss occurring at a high frequency (a high directional antenna is indispensable). A narrow beam width generated by the high directional antenna reduces interference. The small wavelength of a THz signal allows a larger number of antenna elements to be integrated with a device and BS operating in this band. Therefore, an advanced adaptive arrangement technology capable of overcoming a range limitation may be used.

Optical Wireless Technology

Optical wireless communication (OWC) technology is planned for 6G communication in addition to RF based communication for all possible device-to-access networks. This network is connected to a network-to-backhaul/fronthaul network connection. OWC technology has already been used since 4G communication systems but will be more widely used to satisfy the requirements of the 6G communication system. OWC technologies such as light fidelity/visible light communication, optical camera communication and free space optical (FSO) communication based on wide band are well-known technologies. Communication based on optical wireless technology may provide a very high data rate, low latency and safe communication. Light detection and ranging (LiDAR) may also be used for ultra high resolution 3D mapping in 6G communication based on wide band.

FSO Backhaul Network

The characteristics of the transmitter and receiver of the FSO system are similar to those of an optical fiber network. Accordingly, data transmission of the FSO system similar to that of the optical fiber system. Accordingly, FSO may be a good technology for providing backhaul connection in the 6G system along with the optical fiber network. When FSO is used, very long-distance communication is possible even at a distance of 10,000 km or more. FSO supports mass backhaul connections for remote and non-remote areas such as sea, space, underwater and isolated islands. FSO also supports cellular base station connections.

Massive MIMO Technology

One of core technologies for improving spectrum efficiency is MIMO technology. When MIMO technology is improved, spectrum efficiency is also improved. Accordingly, massive MIMO technology will be important in the 6G system. Since MIMO technology uses multiple paths, multiplexing technology and beam generation and management technology suitable for the THz band should be significantly considered such that data signals are transmitted through one or more paths.

Blockchain

A blockchain will be important technology for managing large amounts of data in future communication systems. The blockchain is a form of distributed ledger technology, and distributed ledger is a database distributed across numerous nodes or computing devices. Each node duplicates and stores the same copy of the ledger. The blockchain is managed through a peer-to-peer (P2P) network. This may exist without being managed by a centralized institution or server. Blockchain data is collected together and organized into blocks. The blocks are connected to each other and protected using encryption. The blockchain completely complements large-scale IoT through improved interoperability, security, privacy, stability and scalability. Accordingly, the blockchain technology provides several functions such as interoperability between devices, high-capacity data traceability, autonomous interaction of different IoT systems, and large-scale connection stability of 6G communication systems.

3D Networking

The 6G system integrates terrestrial and public networks to support vertical expansion of user communication. A 3D BS will be provided through low-orbit satellites and UAVs. Adding new dimensions in terms of altitude and related degrees of freedom makes 3D connections significantly different from existing 2D networks.

Quantum Communication

In the context of the 6G network, unsupervised reinforcement learning of the network is promising. The supervised learning method cannot label the vast amount of data generated in 6G. Labeling is not required for unsupervised learning. Thus, this technique can be used to autonomously build a representation of a complex network. Combining reinforcement learning with unsupervised learning may enable the network to operate in a truly autonomous way.

Unmanned aerial vehicle

An unmanned aerial vehicle (UAV) or drone will be an important factor in 6G wireless communication. In most cases, a high-speed data wireless connection is provided using UAV technology. A base station entity is installed in the UAV to provide cellular connectivity. UAVs have certain features, which are not found in fixed base station infrastructures, such as easy deployment, strong line-of-sight links, and mobility-controlled degrees of freedom. During emergencies such as natural disasters, the deployment of terrestrial telecommunications infrastructure is not economically feasible and sometimes services cannot be provided in volatile environments. The UAV can easily handle this situation. The UAV will be a new paradigm in the field of wireless communications. This technology facilitates the three basic requirements of wireless networks, such as eMBB, URLLC and mMTC. The UAV can also serve a number of purposes, such as network connectivity improvement, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communication.

Cell-Free Communication

The tight integration of multiple frequencies and heterogeneous communication technologies is very important in the 6G system. As a result, a user can seamlessly move from network to network without having to make any manual configuration in the device. The best network is automatically selected from the available communication technologies. This will break the limitations of the cell concept in wireless communication. Currently, user movement from one cell to another cell causes too many handovers in a high-density network, and causes handover failure, handover delay, data loss and ping-pong effects. 6G cell-free communication will overcome all of them and provide better QoS. Cell-free communication will be achieved through multi-connectivity and multi-tier hybrid technologies and different heterogeneous radios in the device.

Wireless Information and Energy Transfer (WIET)

WIET uses the same field and wave as a wireless communication system. In particular, a sensor and a smartphone will be charged using wireless power transfer during communication. WIET is a promising technology for extending the life of battery charging wireless systems. Therefore, devices without batteries will be supported in 6G communication.

Integration of Sensing and Communication

An autonomous wireless network is a function for continuously detecting a dynamically changing environment state and exchanging information between different nodes. In 6G, sensing will be tightly integrated with communication to support autonomous systems.

Integration of Access Backhaul Network

In 6G, the density of access networks will be enormous. Each access network is connected by optical fiber and backhaul connection such as FSO network. To cope with a very large number of access networks, there will be a tight integration between the access and backhaul networks.

Hologram Beamforming

Beamforming is a signal processing procedure that adjusts an antenna array to transmit radio signals in a specific direction. This is a subset of smart antennas or advanced antenna systems. Beamforming technology has several advantages, such as high signal-to-noise ratio, interference prevention and rejection, and high network efficiency. Hologram beamforming (HBF) is a new beamforming method that differs significantly from MIMO systems because this uses a software-defined antenna. HBF will be a very effective approach for efficient and flexible transmission and reception of signals in multi-antenna communication devices in 6G.

Big Data Analysis

Big data analysis is a complex process for analyzing various large data sets or big data. This process finds information such as hidden data, unknown correlations, and customer disposition to ensure complete data management. Big data is collected from various sources such as video, social networks, images and sensors. This technology is widely used for processing massive data in the 6G system.

Large Intelligent Surface (LIS)

In the case of the THz band signal, since the straightness is strong, there may be many shaded areas due to obstacles. By installing the LIS near these shaded areas, LIS technology that expands a communication area, enhances communication stability, and enables additional optional services becomes important. The LIS is an artificial surface made of electromagnetic materials, and can change propagation of incoming and outgoing radio waves. The LIS can be viewed as an extension of massive MIMO, but differs from the massive MIMO in array structures and operating mechanisms. In addition, the LIS has an advantage such as low power consumption, because this operates as a reconfigurable reflector with passive elements, that is, signals are only passively reflected without using active RF chains. In addition, since each of the passive reflectors of the LIS must independently adjust the phase shift of an incident signal, this may be advantageous for wireless communication channels. By properly adjusting the phase shift through an LIS controller, the reflected signal can be collected at a target receiver to boost the received signal power.

THz Wireless Communication

FIG. 17 is a view showing a THz communication method applicable to the present disclosure.

Referring to FIG. 17 , THz wireless communication uses a THz wave having a frequency of approximately 0.1 to 10 THz (1 THz=1012 Hz), and may mean terahertz (THz) band wireless communication using a very high carrier frequency of 100 GHz or more. The THz wave is located between radio frequency (RF)/millimeter (mm) and infrared bands, and (i) transmits non-metallic/non-polarizable materials better than visible/infrared rays and has a shorter wavelength than the RF/millimeter wave and thus high straightness and is capable of beam convergence.

In addition, the photon energy of the THz wave is only a few meV and thus is harmless to the human body. A frequency band which will be used for THz wireless communication may be a D-band (110 GHz to 170 GHz) or a H-band (220 GHz to 325 GHz) band with low propagation loss due to molecular absorption in air. Standardization discussion on THz wireless communication is being discussed mainly in IEEE 802.15 THz working group (WG), in addition to 3GPP, and standard documents issued by a task group (TG) of IEEE 802.15 (e.g., TG3d, TG3e) specify and supplement the description of this disclosure. The THz wireless communication may be applied to wireless cognition, sensing, imaging, wireless communication, and THz navigation.

Specifically, referring to FIG. 17 , a THz wireless communication scenario may be classified into a macro network, a micro network, and a nanoscale network. In the macro network, THz wireless communication may be applied to vehicle-to-vehicle (V2V) connection and backhaul/fronthaul connection. In the micro network, THz wireless communication may be applied to near-field communication such as indoor small cells, fixed point-to-point or multi-point connection such as wireless connection in a data center or kiosk downloading. Table 5 below shows an example of technology which may be used in the THz wave.

TABLE 5 Transceivers Device Available immature: UTC-PD, RTD and SBD Modulation and coding Low order modulation techniques (OOK, QPSK), LDPC, Reed Soloman, Hamming, Polar, Turbo Antenna Omni and Directional, phased array with low number of antenna elements Bandwidth 69 GHz (or 23 GHz) at 300 GHz Channel models Partially Data rate 100 Gbps Outdoor deployment No Free space loss High Coverage Low Radio Measurements 300 GHz indoor Device size Few micrometers

FIG. 18 is a view showing a THz wireless communication transceiver applicable to the present disclosure.

Referring to FIG. 18 , THz wireless communication may be classified based on the method of generating and receiving THz. The THz generation method may be classified as an optical component or electronic component based technology.

At this time, the method of generating THz using an electronic component includes a method using a semiconductor component such as a resonance tunneling diode (RTD), a method using a local oscillator and a multiplier, a monolithic microwave integrated circuit (MMIC) method using a compound semiconductor high electron mobility transistor (HEMT) based integrated circuit, and a method using a Si-CMOS-based integrated circuit. In the case of FIG. 18 , a multiplier (doubler, tripler, multiplier) is applied to increase the frequency, and radiation is performed by an antenna through a subharmonic mixer. Since the THz band forms a high frequency, a multiplier is essential. Here, the multiplier is a circuit having an output frequency which is N times an input frequency, and matches a desired harmonic frequency, and filters out all other frequencies. In addition, beamforming may be implemented by applying an array antenna or the like to the antenna of FIG. 18 . In FIG. 18 , IF represents an intermediate frequency, a tripler and a multiplier represents a multiplier, PA represents a power amplifier, and LNA represents a low noise amplifier, and PLL represents a phase-locked loop.

FIG. 19 is a view showing a THz signal generation method applicable to the present disclosure. FIG. 20 is a view showing a wireless communication transceiver applicable to the present disclosure.

Referring to FIGS. 19 and 20 , the optical component-based THz wireless communication technology means a method of generating and modulating a THz signal using an optical component. The optical component-based THz signal generation technology refers to a technology that generates an ultrahigh-speed optical signal using a laser and an optical modulator, and converts it into a THz signal using an ultrahigh-speed photodetector. This technology is easy to increase the frequency compared to the technology using only the electronic component, can generate a high-power signal, and can obtain a flat response characteristic in a wide frequency band. In order to generate the THz signal based on the optical component, as shown in FIG. 19 , a laser diode, a broadband optical modulator, and an ultrahigh-speed photodetector are required. In the case of FIG. 19 , the light signals of two lasers having different wavelengths are combined to generate a THz signal corresponding to a wavelength difference between the lasers. In FIG. 19 , an optical coupler refers to a semiconductor component that transmits an electrical signal using light waves to provide coupling with electrical isolation between circuits or systems, and a uni-travelling carrier photo-detector (UTC-PD) is one of photodetectors, which uses electrons as an active carrier and reduces the travel time of electrons by bandgap grading. The UTC-PD is capable of photodetection at 150 GHz or more. In FIG. 20 , an erbium-doped fiber amplifier (EDFA) represents an optical fiber amplifier to which erbium is added, a photo detector (PD) represents a semiconductor component capable of converting an optical signal into an electrical signal, and OSA represents an optical sub assembly in which various optical communication functions (e.g., photoelectric conversion, electrophotic conversion, etc.) are modularized as one component, and DSO represents a digital storage oscilloscope.

FIG. 21 is a view showing a transmitter structure applicable to the present disclosure. FIG. 22 is a view showing a modulator structure applicable to the present disclosure.

Referring to FIGS. 21 and 22 , generally, the optical source of the laser may change the phase of a signal by passing through the optical wave guide. At this time, data is carried by changing electrical characteristics through microwave contact or the like. Thus, the optical modulator output is formed in the form of a modulated waveform. A photoelectric modulator (O/E converter) may generate THz pulses according to optical rectification operation by a nonlinear crystal, photoelectric conversion (O/E conversion) by a photoconductive antenna, and emission from a bunch of relativistic electrons. The terahertz pulse (THz pulse) generated in the above manner may have a length of a unit from femto second to pico second. The photoelectric converter (O/E converter) performs down conversion using non-linearity of the component.

Given THz spectrum usage, multiple contiguous GHz bands are likely to be used as fixed or mobile service usage for the terahertz system. According to the outdoor scenario criteria, available bandwidth may be classified based on oxygen attenuation 10{circumflex over ( )} 2 dB/km in the spectrum of up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of several band chunks may be considered. As an example of the framework, if the length of the terahertz pulse (THz pulse) for one carrier (carrier) is set to 50 ps, the bandwidth (BW) is about 20 GHz.

Effective down conversion from the infrared band to the terahertz band depends on how to utilize the nonlinearity of the O/E converter. That is, for down-conversion into a desired terahertz band (THz band), design of the photoelectric converter (O/E converter) having the most ideal non-linearity to move to the corresponding terahertz band (THz band) is required. If a photoelectric converter (O/E converter) which is not suitable for a target frequency band is used, there is a high possibility that an error occurs with respect to the amplitude and phase of the corresponding pulse.

In a single carrier system, a terahertz transmission/reception system may be implemented using one photoelectric converter. In a multi-carrier system, as many photoelectric converters as the number of carriers may be required, which may vary depending on the channel environment. Particularly, in the case of a multi-carrier system using multiple broadbands according to the plan related to the above-described spectrum usage, the phenomenon will be prominent. In this regard, a frame structure for the multi-carrier system can be considered. The down-frequency-converted signal based on the photoelectric converter may be transmitted in a specific resource region (e.g., a specific frame). The frequency domain of the specific resource region may include a plurality of chunks. Each chunk may be composed of at least one component carrier (CC).

Artificial Intelligence System

FIG. 23 is a view showing a perceptron architecture in an artificial neural network applicable to the present disclosure. In addition, FIG. 24 is a view showing an artificial neural network architecture applicable to the present disclosure.

As described above, an artificial intelligence system may be applied to a 6G system. Herein, as an example, the artificial intelligence system may operate based on a learning model corresponding to the human brain, as described above. Herein, a paradigm of machine learning, which uses a neural network architecture with high complexity like artificial neural network, may be referred to as deep learning. In addition, neural network cores, which are used as a learning scheme, are mainly a deep neural network (DNN), a convolutional deep neural network (CNN), and a recurrent neural network (RNN). Herein, as an example referring to FIG. 23 , an artificial neural network may consist of a plurality of perceptions. Herein, when an input vector x={x1, x2, . . . , xd} is input, each component is multiplied by a weight {W1, W2, . . . , Wd}, results are all added up, and then an activation function 60 is applied, of which the overall process may be referred to as a perceptron. For a large artificial neural network architecture, when expanding the simplified perceptron structure illustrated in FIG. 23 , an input may be applied to different multidimensional perceptrons. For convenience of explanation, an input value or an output value will be referred to as a node.

Meanwhile, the perceptron structure illustrated in FIG. 23 may be described to consist of a total of 3 layers based on an input value and an output value. An artificial neural network, which has H (d+1)-dimensional perceptrons between a 1st layer and a 2nd layer and K (H+1)-dimensional perceptrons between the 2nd layer and a 3rd layer, may be expressed as in FIG. 24 .

Herein, a layer, in which an input vector is located, is referred to as an input layer, a layer, in which a final output value is located, is referred to as an output layer, and all the layers between the input layer and the output layer are referred to as hidden layers. As an example, 3 layers are disclosed in FIG. 24 , but since an input layer is excluding in counting the number of actual artificial neural network layers, it can be understood that the artificial neural network illustrated in FIG. 23 has a total of 2 layers. An artificial neural network is constructed by connecting perceptrons of a basic block two-dimensionally.

The above-described input layer, hidden layer and output layer are commonly applicable not only to multilayer perceptrons but also to various artificial neural network architectures like CNN and RNN, which will be described below. As there are more hidden layers, an artificial neural network becomes deeper, and a machine learning paradigm using a sufficiently deep artificial neural network as a learning model may be referred to as deep learning. In addition, an artificial neural network used for deep learning may be referred to as a deep neural network (DNN).

FIG. 25 is a view showing a deep neural network applicable to the present disclosure.

Referring to FIG. 25 , a deep neural network may be a multilayer perceptron consisting of 8 layers (hidden layers+output layer). Herein, the multilayer perceptron structure may be expressed as a fully-connected neural network. In a fully-connected neural network, there may be no connection between nodes in a same layer and only nodes located in neighboring layers may be connected with each other. A DNN has a fully-connected neural network structure combining a plurality of hidden layers and activation functions so that it may be effectively applied for identifying a correlation characteristic between an input and an output. Herein, the correlation characteristic may mean a joint probability between the input and the output.

FIG. 26 is a view showing a convolutional neural network applicable to the present disclosure. In addition, FIG. 27 is a view showing a filter operation of a convolutional neural network applicable to the present disclosure.

As an example, depending on how to connect a plurality of perceptrons, it is possible to form various artificial neural network structures different from the above-described DNN. Herein, in the DNN, nodes located in a single layer are arranged in a one-dimensional vertical direction. However, referring to FIG. 26 , it is possible to assume a two-dimensional array of w horizontal nodes and h vertical nodes (the convolutional neural network structures of FIG. 26 ). In this case, since a weight is applied to each connection in a process of connecting one input node to a hidden layer, a total of h×w weights should be considered. As there are h x w nodes in an input layer, a total of h²w² weights may be needed between two neighboring layers.

Furthermore, as the convolutional neural network of FIG. 26 has the problem of exponential increase in the number of weights according to the number of connections, the presence of a small filter may be assumed instead of considering every mode of connections between neighboring layers. As an example, as shown in FIG. 27 , weighted summation and activation function operation may be enabled for a portion overlapped by a filter.

At this time, one filter has a weight corresponding to a number as large as its size, and learning of a weight may be performed to extract and output a specific feature on an image as a factor. In FIG. 27 , a 3×3 filter may be applied to a top rightmost 3×3 area of an input layer, and an output value, which is a result of the weighted summation and activation function operation for a corresponding node, may be stored at z₂₂.

Herein, as the above-described filter scans the input layer while moving at a predetermined interval horizontally and vertically, a corresponding output value may be put a position of a current filter. Since a computation method is similar to a convolution computation for an image in the field of computer vision, such a structure of deep neural network may be referred to as a convolutional neural network (CNN), and a hidden layer created as a result of convolution computation may be referred to as a convolutional layer. In addition, a neural network with a plurality of convolutional layers may be referred to as a deep convolutional neural network (DCNN).

In addition, at a node in which a current filter is located in a convolutional layer, a weighted sum is calculated by including only a node in an area covered by the filter and thus the number of weights may be reduced. Accordingly, one filter may be so used as to focus on a feature of a local area. Thus, a CNN may be effectively applied to image data processing for which a physical distance in a two-dimensional area is a crucial criterion of determination. Meanwhile, a CNN may apply a plurality of filters immediately before a convolutional layer and create a plurality of output results through a convolution computation of each filter.

Meanwhile, depending on data properties, there may be data of which a sequence feature is important. A recurrent neural network structure may be a structure obtained by applying a scheme, in which elements in a data sequence are input one by one at each timestep by considering the distance variability and order of such sequence datasets and an output vector (hidden vector) output at a specific timestep is input with a very next element in the sequence, to an artificial neural network.

FIG. 28 is a view showing a neural network architecture with a recurrent loop applicable to the present disclosure. FIG. 29 is a view showing an operational structure of a recurrent neural network applicable to the present disclosure.

Referring to FIG. 28 , a recurrent neural network (RNN) may have a structure which applies a weighted sum and an activation function by inputting hidden vectors {z₁ ^((t−1)), z₂ ^(t−1)), . . . , z_(H) ^((t−1))} of an immediately previous timestep t−1 during a process of inputting elements {x₁ ^((t)), x₂ ^((t)), . . . , x_(d) ^((t))} of a timestep t in a data sequence into a fully connected neural network. The reason why such hidden vectors are forwarded to a next timestep is because information in input vectors at previous timesteps is considered to have been accumulated in a hidden vector of a current timestep.

In addition, referring to FIG. 29 , a recurrent neural network may operate in a predetermined timestep order for an input data sequence. Herein, as a hidden vector {z₁ ⁽¹⁾, z₂ ⁽¹⁾, . . . , z_(H) ⁽¹⁾} at a time of inputting an input vector {x₁ ^((t)), x₂ ^((t)), . . . , x_(d) ^((t))} of timestep 1 into a recurrent neural network is input together with an input vector {x_(i) ⁽²⁾, x₂ ⁽²⁾, . . . , x_(d) ⁽²⁾} of timestep 2, a vector {z₁ ⁽²⁾, z₂ ⁽²⁾, . . . , z_(H) ⁽²⁾} of a hidden layer is determined through a weighted sum and an activation function. Such a process is iteratively performed at timestep 2, timestep 3 and until timestep T.

Meanwhile, when a plurality of hidden layers are allocated in a recurrent neural network, this is referred to as a deep recurrent neural network (DRNN). A recurrent neural network is so designed as to effectively apply to sequence data (e.g., natural language processing).

Apart from DNN, CNN and RNN, other neural network cores used as a learning scheme include various deep learning techniques like restricted Boltzmann machine (RBM), deep belief networks (DBN) and deep Q-Network, and these may be applied to such areas as computer vision, voice recognition, natural language processing, and voice/signal processing.

Recently, there are attempts to integrate AI with a wireless communication system, but these are concentrated in an application layer and a network layer and, especially in the case of deep learning, in a wireless resource management and allocation filed. Nevertheless, such a study gradually evolves to an MAC layer and a physical layer, and there are attempts to combine deep learning and wireless transmission especially in a physical layer. As for a fundamental signal processing and communication mechanism, AI-based physical layer transmission means application of a signal processing and communication mechanism based on an AI driver, instead of a traditional communication framework. For example, it may include deep learning-based channel coding and decoding, deep learning-based signal estimation and detection, deep learning-based MIMO mechanism, and AI-based resource scheduling and allocation.

Specific Embodiment of the Present Disclosure

The present disclosure relates to a method and apparatus for performing cell reselection in a wireless communication system. Specifically, the present disclosure describes a technology related to an efficient cell reselection method using federated learning artificial intelligence.

Various embodiments described below may be easily applied when a terminal (UE) intends to perform cell reselection or handover in an environment where various communication nodes coexist in a wireless communication system. In the following description, cell reselection may be used interchangeably with handover.

When a terminal performs cell reselection in a wireless communication system, it is desirable for a terminal to consume the lowest possible power and access a base station as quickly as possible.

However, due to obstacles such as numerous wireless devices and high-rise buildings existing in the wireless communication environment, the terminal may not immediately access a target base station during cell reselection, and may perform cell reselection several times or frequently. Here, the wireless device may include many terminals, self-driving or interne of things (IoT) devices. In addition, when the terminal must attempt to access the base station several times to succeed due to the wireless device and the environment, the terminal may perform frequent access to the base station according to overlap of many base stations and repeaters. In addition, the terminal may not perform efficient resource management due to frequent access to the base station, and thus power consumption may increase. In addition, there may be a problem in that the information of the base station according to the surrounding environment or the change of the radio channel does not cope with the situation and environment. In addition, there is a problem in that information accessed by the terminals does not contribute to efficient access to the base station.

The present disclosure relates to implementation of an artificial intelligence-based efficient base station access method and system through context awareness, and can increase efficiency such as resource management of a terminal and a base station and power consumption of the terminal.

FIG. 30 is a diagram illustrating information for cell reselection applicable to the present disclosure. Referring to FIG. 30 , a base station may broadcast a master information block (MIB), system information block 1 (SIB1), and system information (SI) to UEs. Here, the SI may include system information block (SIB) 2, SIB3, SIB4, SIB5, SIB6, SIB7, SIB8, and the like.

The MIB may include information for enabling a UE to access a cell. Specifically, it may include a downlink bandwidth, a system frame number (SFN), and the like. SIB1 may include information related to whether to allow cell access and scheduling information of other SIBs. SIB2 may include radio resource configuration information. SIB3 may include all types of information commonly used for cell reselection. That is, it may include information commonly used for intra-frequency, inter-frequency, and inter-radio access technology (inter-RAT) cell reselection. In addition, it may include intra-frequency cell reselection information. SIB4 may include neighbor cell information for intra-frequency cell reselection. SIB5 may include frequency and neighbor cell information for inter-frequency cell reselection. SIB6 may include information for inter-radio access technology frequency cell reselection.

FIG. 31 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. A first base station (CID #1) 3104 may broadcast an SIB to a UE 3102 (S3101). That is, the first base station 3104 may transmit the SIB including SIB parameters to the UE through a broadcasting channel (BCCH). The UE may be connected to the first base station 3104 based on the SIB parameters received from the first base station 3104. Here, the SIB parameters may include parameters related to cell reselection, which will be described later.

After the UE is connected to the first base station, the UE may perform a cell reselection procedure for a second base station based on a triggering condition for cell reselection. For example, the triggering condition for cell reselection may vary and are not limited to a specific condition.

Here, the UE 3102 may perform cell reselection based on the SIB parameters received from the first base station 3104. The UE may transmit the parameter information related to cell reselection to a second base station (CID #2) 3106 (S3103). Also, in step S3103, the UE 3102 may transmit information about the reselected cell to the second base station 3106 through a random access channel (RACH). In addition, the UE may transmit cell reselection-related parameters to the second base station through another message or a separate message, which will be described later.

The second base station 3106 may transmit information about the reselected cell based on the information received from the UE (S3105). More specifically, the second base station 3106 may transmit information necessary to connect the UE to the second base station to the UE through the SIB based on the information received from the UE. As a specific example, the second base station may receive the parameter information related to cell reselection from a plurality of UEs, and, based on this, generate information necessary to connect the UE to the second base station, which will be described later. The UE may perform cell reselection for the second base station using the information received through the SIB.

FIG. 32 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. A parameter for cell reselection may be updated based on a learning model. For example, the learning model may be a federated learning (FL) model. The federated learning model may be a machine learning technique that trains an algorithm on multiple UEs or servers having local data samples or information, without exchanging data samples or information. In the following, for convenience of description, a method of updating cell reselection parameters based on a federated learning model is described, but may not be limited thereto.

Referring to FIG. 32 , a UE 3202 may receive information for effective access from a base station through SIB information and new message information. In step S3201, the UE may receive an SIB from a first base station (CID #1) 3204. For example, the UE 3202 may receive SIB parameters from the first base station 3204 through a BCCH.

Also, in step S3201, the UE may receive new message information from the first base station. Here, the new message information may be information received along with the SIB parameters through the BCCH. As another example, the new message information may be information configured as the SIB parameters, and is not limited to the above-described embodiment. For example, the new message information may include parameter information related to cell reselection. As a more specific example, the new message information may include at least one of α^(BS), β^(BS), W^(BS) or AI_(Ind), but may also include other information.

Here, α^(BS) and β^(BS) may include parameter information related to cell reselection learning models of a plurality of UEs. W^(BS) may mean a weight of cell reselection learning models for α^(BS) and β^(BS). AI_(Ind) may include information indicating whether a reception UE uses a cell reselection learning model. More specifically, the base station may receive parameter information related to a learning model from each UE, generate α^(BS) and β^(BS) which are parameters related to cell reselection, and transmit them to the UE.

In addition, the UE may receive radio channel environment information from the first base station. The radio channel environment information may include environment and situation information of the UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI).

The UE may perform cell reselection based on the above information. For example, the UE may update α^(BS) and β^(BS) by reflecting the received radio channel environment information. As another example, α^(BS) and β^(BS) may be updated by reflecting the radio channel environment information and the weight W^(BS) of the cell reselection learning model. The UE may perform cell reselection based on the updated parameters.

The UE 3202 may perform cell reselection based on a triggering condition for cell reselection. In step S3203, the UE 3202 may transmit information related to the reselected cell to a second base station 3206 after cell reselection. For example, the UE may transmit information about the reselected cell through a random access channel (RACH). The second base station may check information for cell reselection received from the UE and generate information for cell reselection. Thereafter, the second base station may broadcast the generated information to the UE through the SIB (S3205).

Also, in step S3203, the UE 3202 may transmit the updated message information to the second base station 3206. That is, the UE may update message information based on received new message information, environment, situation information, etc., and transmit the message information to the second base station. For example, the updated message information may be transmitted to the second base station in a random access procedure. As another example, the updated message information may be transmitted together with a separate message or another message, and is not limited to the above-described embodiment. As a more specific example, the UE may perform an update from α^(BS) and β^(BS) received from the first base station, and the updated message information may include α^(BS) and β^(BS). The UE may transmit the updated message information α_(i), and β_(i) to the second base station. Thereafter, the second base station may broadcast cell reselection related information generated based on α_(i) and β_(i) to the UE through the SIB (S3205).

FIG. 33 is a diagram illustrating a method of receiving parameter information of various terminals (UEs) by a base station applicable to the present disclosure. Referring to FIG. 33 , a base station 3308 may receive α₁ and β₁ from UE 1 3302. Here, α₁ and β₁ may be parameters related to the cell reselection learning model generated by UE 1 3302. Alternatively, α₁ and β₁ may be information generated through an update based on parameter information related to the cell reselection learning model received by UE 1 from the base station. In addition, each UE may also generate parameters related to cell reselection based on the same method and transmit them to the base station. For example, the base station may receive α₂ and β₂ from UE 2 3304. In addition, the base station 3308 may receive α₃ and β₃ from UE 3. Similarly, the base station 3308 may receive α_(u) and β_(u) from the UE U 3306. That is, the base station 3308 may receive parameter information related to cell reselection of a plurality of UEs.

The base station may generate α^(BS) and β^(BS) based on the received parameter information related to cell reselection of various UEs. α^(BS) and β^(BS) are shown in Equation 1 below.

$\begin{matrix} \begin{matrix} {\alpha^{BS} = \frac{{\sum}_{i = 1}^{U}\alpha_{i}}{U}} & {\beta^{BS} = \frac{{\sum}_{i = 1}^{U}\beta_{i}}{U}} \end{matrix} & {{Equation}1} \end{matrix}$

Here, U may mean the number of UEs that have provided parameter information related to cell reselection in relation to the parameter information related to cell reselection of several UEs received by the base station. Here, α^(BS) may mean an average of α of UEs received by the base station. β^(BS) may mean an average of β of UEs received by the base station.

The base station may generate the weight W^(BS) based on the received learning model parameters of the plurality of UES. W^(BS) is shown in Equation 2 below.

$\begin{matrix} \begin{matrix} {{J(w)} = {\sum\limits_{k = 1}^{u}{❘{d_{k} - {x_{k}(w)}}❘}^{2}}} \\ {w^{BS} = {\arg\min\limits_{w}{J(w)}}} \end{matrix} & {{Equation}2} \end{matrix}$

d_(k) may mean a value (trained information) measured by the base station in consideration of the situation and environment. x_(k)(w) may mean values of α_(k) and β_(k) of a UE k. J(w) may mean a value obtained by adding all squares of differences between d_(k) and x_(k)(w). W^(BS) may mean an estimator that makes J(w) a minimum value.

The base station may broadcast the generated α^(BS), β^(BS), and W^(BS) to the UEs. In addition, the base station may broadcast AI_(Ind), which is information indicating whether the reception UE uses the learning model, to the UEs.

In addition, the base station may transmit radio channel environment information to each UE. The radio channel environment information may include environment and situation information of a corresponding UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI).

FIG. 34 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. In step S3401, a UE may receive an SIB and radio channel environment information from a first base station. For example, the UE may receive SIB parameters from the first base station through a BCCH.

Also, the UE may receive new message information from the first base station. According to an example, the new message information may be information received together with the SIB parameters. As another example, the new message information may be information configured as SIB parameters, and is not limited to the above-described embodiment.

The new message information may include at least one of α^(BS), β^(BS), W^(BS), or AI_(Ind), but may further include other information. α^(BS) and β^(BS) may include parameter information related to cell reselection of other UEs. According to an example, α^(BS) and β^(BS) may be parameters of a beta distribution. Here, α^(BS) and β^(BS) may be information generated by the base station receiving parameter information related to cell reselection of a plurality of UEs. According to an example, α^(BS) and β^(BS) may be generated by the base station receiving beta distribution parameters α and β of the plurality of UEs and obtaining an average. W^(BS) may mean a weight based on α^(BS) and β^(BS). For example, the weight may be a value that minimizes a difference between a value measured by the base station and the first parameter.

AI_(Ind) may include information indicating whether to use a cell reselection learning model. For example, the UE may perform an update using the cell reselection learning model only when AI_(Ind) including information indicating whether to use the cell reselection learning model is received. As another example, when the UE receives AI_(Ind) including information indicating that the cell reselection learning model is not used, the UE may not perform an update using the cell re-selection learning model. Here, the UE may perform cell reselection based on an existing cell reselection procedure without using a cell reselection learning model when a triggering condition for cell reselection is satisfied.

In addition, the UE may receive radio channel environment information from the first base station. The radio channel environment information may include environment and situation information of the UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI).

In step S3403, the UE may update at least one first parameter included in the received SIB to a second parameter by reflecting radio channel environment information. According to an example, the first parameter included in the SIB received by the UE may be a parameter related to a cell reselection learning model of a plurality of UEs. As a more specific example, the first parameter included in the SIB received by the UE may be beta distribution parameters α^(BS) and β^(BS) generated and transmitted by the base station. The UE may update α^(BS) and β^(BS) as the second parameters in the cell reselection learning model by reflecting the radio channel environment information received from the base station. As a more specific example, the UE may update α^(BS) and β^(BS) as the second parameters by reflecting radio channel environment information and weight information received from the base station, respectively.

In step S3405, the UE may reselect the second base station based on the updated at least one or more second parameters. For example, the UE may perform cell reselection based on a triggering condition for cell reselection. For example, the UE may select a maximum value by randomly sampling a beta distribution based on the updated second parameter, and reselect a cell based on the selected maximum value.

After cell reselection, the UE may transmit information related to the reselected cell to the second base station. For example, the UE may transmit information about the reselected cell through a random access channel (RACH). The second base station may check information for cell reselection received from the UE and generate information for cell reselection. Thereafter, the second base station may broadcast the generated information to the UE through the SIB.

In addition, the UE may transmit the updated message information to the second base station. For example, the updated message information may be transmitted to the second base station in a random access procedure. As another example, the updated message information may be transmitted together with a separate message or another message, and is not limited to the above-described embodiment. As a more specific example, the UE may perform an update from α^(BS) and β^(BS) received from the first base station, and the updated message information may include α_(i) and β_(i). The UE may transmit the updated message information α_(i) and β_(i) to the second base station. After that, the second base station may broadcast cell reselection related information generated based on α_(i) and β_(i) to the UE through the SIB.

FIG. 35 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. In step S3501, a base station may receive parameter information related to a cell reselection learning model from a plurality of UEs. For example, the base station may receive α₁ and β₁ from UE 1. Here, α₁ and β₁ may be parameters related to the cell reselection learning model generated by UE 1. Alternatively, α₁ and β₁ may be information generated through an update based on the parameter information related to the cell reselection learning model received by UE 1 from the base station. In addition, each UE may also generate parameters related to cell reselection based on the same method and transmit them to the base station. For example, the base station may receive α₂ and β₂ from UE 2. In addition, the base station may receive α₃ and β₃ from UE 3. Similarly, the base station may receive α_(u) and β_(u) from UE U. That is, the base station may receive the parameter information related to cell reselection of a plurality of UEs.

In step S3503, the base station may generate at least one first parameter for the cell reselection learning model based on the received parameter information. For example, the base station may generate α^(BS) and β^(BS) based on the received parameter information related to cell reselection of several UEs. Equation related to this is the same as Equation 1 described above. In addition, the base station may generate a weight W^(BS) based on the received learning model parameters of a plurality of UEs. W^(BS) may be the same as Equation 2 described above. The base station may broadcast the generated α^(BS), β^(BS) and W^(BS) to the UEs. In addition, the base station may broadcast AI_(Ind), which is information indicating whether the reception UE uses the learning model, to the UEs.

In step S3505, the base station may transmit the SIB including the at least one or more first parameters to the first UE. For example, the base station may transmit SIB parameters to the UE through a BCCH. In addition, the base station may transmit new message information to the UE. For example, the new message information may be information transmitted together with the SIB parameters. As another example, the new message information may be information configured as SIB parameters, and is not limited to the above-described embodiment. The new message information may include at least one of α^(BS), β^(BS), W^(BS), or AI_(Ind), but may further include other information. α^(BS) and β^(BS) may include parameter information related to cell reselection of other UEs. According to an example, α^(BS) and β^(BS) may be beta distribution parameters. Here, α^(BS) and β^(BS) may be information generated by the base station receiving parameter information related to cell reselection of a plurality of UEs. According to an example, α^(BS) and β^(BS) may be generated by the base station receiving beta distribution parameters α and β of a plurality of UEals and obtaining an average. W^(BS) may mean a weight based on α^(BS) and β^(BS).

AI_(Ind) may include information indicating whether to use a cell reselection learning model. For example, the UE may perform an update using the cell reselection learning model only when AI_(Ind) including information indicating whether to use the cell reselection learning model is received. As another example, when the UE receives AI_(Ind) including information indicating that the cell reselection learning model is not used, the UE may not perform an update using the cell reselection learning model. Here, the UE may perform cell reselection based on an existing cell reselection procedure without using a cell reselection learning model when a triggering condition for cell reselection is satisfied.

In step S3507, the base station may transmit radio channel environment information to the first UE. The radio channel environment information may include environment and situation information of the UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI). The UE1 may perform cell reselection in consideration of the radio channel environment information. In addition, the UE may perform cell reselection in consideration of a weight.

FIG. 36 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. Referring to FIG. 36 , a UE may receive information for effective access from a base station through SIB information and new message information. In step S3601, a UE 3602 may receive an SIB from a first base station (CID #1) 3604. For example, the UE 3602 may receive SIB parameters from the first base station 3604 through a BCCH.

Also, in step S3601, the UE may receive new message information from the first base station. The new message information may include at least one of α^(BS), β^(BS), W^(BS), or AI_(Ind), but may also include other information.

Here, α^(BS) and β^(BS) may include parameter information related to cell reselection of other UEls. W^(BS) may mean a weight for α^(BS) and β^(BS. AI) _(Ind) may include information indicating whether the reception UE uses a learning model. More specifically, the base station may receive parameter information related to a learning model from each UE, generate α^(BS) and β^(BS) which are cell reselection-related parameters, and transmit them to the UE.

In addition, the UE may receive radio channel environment information from the first base station. The radio channel environment information may include environment and situation information of the UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI).

In step S3603, the UE may perform a Thompson sampling procedure. Thompson sampling may select the largest value from among sampled values by applying the accumulated α and β to a beta distribution. Equation 3 below shows Thomson sampling.

$\begin{matrix} {{{{Beta}\left( {x{❘{a,b}}} \right)} = {\frac{1}{B\left( {a,b} \right)}{x^{({a - 1})}\left( {1 - x} \right)}^{({b - 1})}}},{{B\left( {a,b} \right)} = {\int_{0}^{1}{{x^{({a - 1})}\left( {1 - x} \right)}^{({b - 1})}{dx}}}}} & {{Equation}3} \end{matrix}$

The environment and situation information of the corresponding UE may not be applied to the accumulated values of α and β received by the UE. The UE may apply and infer the environment and situation to create new α and β values and update them to new Beta(α, β). Based on this updated information, the UE may perform random sampling and select a maximum value from among the values. The UE may reselect a cell based on the selected maximum value.

The UE may perform cell reselection based on a triggering condition for cell reselection. In step S3605, after cell reselection, the UE may transmit information related to the reselected cell to the second base station 3606. For example, the UE may transmit information about the reselected cell through a random access channel (RACH). The second base station 3606 may check the information for cell reselection received from the UE 3602 and generate the information for cell reselection. Thereafter, the second base station may broadcast the generated information to the UE through the SIB (S3607).

Also, the UE 3602 may transmit the updated message information to the second base station 3606. For example, the updated message information may be transmitted to the second base station 3606 in a random access procedure. As another example, the updated message information may be transmitted together with a separate message or another message, and is not limited to the above-described embodiment. For example, the UE may perform an update from α^(BS) and β^(BS) received from the first base station, and the updated message information may include α_(i) and β_(i). Here, α_(i) and β_(i) may mean information updated in the corresponding UE. The updated message information may include beta distribution parameters updated by reflecting radio channel environment information of the corresponding UE. The UE may transmit the updated message information α_(i) and β_(i) to the second base station. Thereafter, the second base station may broadcast cell reselection-related information generated based on α_(i) and β_(i) to the UE through the SIB (S3607). The UE 3602 may receive the SIB from the second base station (CID #2) 3606. For example, the UE 3602 may receive SIB parameters from the second base station 3606 through a BCCH.

FIG. 37 is a diagram illustrating an example of a cell reselection procedure applicable to the present disclosure. In step S3701, a UE may receive a global model capable of cell selection or reselection in SIB information from a base station. According to an example, the global model may include cell reselection parameter information of a plurality of UEs. In addition, the global model may include parameters generated by the base station based on beta distribution parameters of a plurality of UEs. Also, the global model may include weights for parameters related to cell reselection of other UEs. In addition, the global model may include information instructing the UE to use a cell reselection learning model.

In addition, the UE may receive radio channel environment information from the base station. The radio channel environment information may include environment and situation information of the UE. For example, the radio channel environment information may include radio signal strength (RSS), a global positioning system (GPS), time, date, and the like. As another example, the radio channel environment information may mean channel state information (CSI).

In step S3703, the UE may update the beta distribution Beta(α, β) by inference based on environment and situation information, parameters received from the base station, and weight values received from the base station. Here, the parameters received from the base station may be parameters α and β of a beta distribution. For example, the UE may select a maximum value from among values obtained by randomly sampling beta distributions.

In step S3705, the UE may select or reselect a cell based on the above-described maximum value during cell selection or cell reselection. In step S3707, after the UE selects a cell or reselects a cell, if the receive power of the UE is maintained or improved for a predetermined time, the UE may perform α+1 operation. When the receive power of the UE is decreased, the UE may perform β+1 operation.

In step S3709, the UE may update the beta distribution Beta(α, β), which is a local model. For example, the local model may mean a beta distribution updated by reflecting the radio channel environment of the corresponding UE. As another example, the local model may mean a beta distribution updated by reflecting the weight received from the base station. In step S3711, the UE may transmit the updated local model to the base station. For example, the UE may transmit the updated local model through a random access channel (RACH). In step S3713, the base station may learn a global model based on the received local model. For example, the base station may check the local model received from the UE and generate information for cell reselection. More specifically, the base station may generate beta distribution parameters, which are information for cell reselection, by obtaining an average based on the beta distribution parameters received from a plurality of UEs. According to another example, the base station may calculate an optimal weight value based on beta distribution parameters received from a plurality of UEs. Thereafter, the base station may broadcast the generated information to the UE through the SIB.

FIG. 38 is a diagram illustrating an example of a parameter predictor applicable to the present disclosure. Variables may be input to the parameter predictor. Here, the variables may include situation characteristics of the UE, environment characteristics, and the like. Here, the situation characteristics may include a cell ID (cell_id), beam information, time, date, and the like. Also, environmental characteristics may include RSS, GPS, and the like. Also, the variables may include parameters related to a cell reselection learning model generated by the base station based on the parameters related to the cell reselection learning model of a plurality of UEs. For example, the base station may receive α and β related information from a plurality of UEs, generate cell reselection-related parameters α^(BS) and β^(BS) through a learning model, and transmit them to the parameter predictor. The base station may transmit W^(BS) to the parameter predictor as a weight for αBS and βBS. Also, the parameter predictor may receive radio channel environment information. The radio channel environment information may include the above-described environment and situation information of the UE.

The parameter predictor may update the parameters related to the cell reselection learning model received from the base station based on the weight received from the base station and the radio channel environment. For example, the parameter predictor may update α^(BS) and β^(BS) received from the base station based on the W^(BS) and radio channel environment.

The parameter predictor may cope with the environment and situation by inference using the weight learned from the base station by applying the environment and situation information of the UE before applying α and β accumulated in Thompson sampling to the beta distribution. In addition, the parameter predictor may enable effective access to the base station by applying the environment and situation information of the UE.

As the examples of the proposal method described above may also be included in one of the implementation methods of the present disclosure, it is an obvious fact that they may be considered as a type of proposal methods. In addition, the proposal methods described above may be implemented individually or in a combination (or merger) of some of them. A rule may be defined so that information on whether or not to apply the proposal methods (or information on the rules of the proposal methods) is notified from a base station to a terminal through a predefined signal (e.g., a physical layer signal or an upper layer signal).

The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential features described in the present disclosure. Therefore, the above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the present disclosure should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure. In addition, claims having no explicit citation relationship in the claims may be combined to form an embodiment or to be included as a new claim by amendment after filing.

The embodiments of the present disclosure are applicable to various radio access systems. Examples of the various radio access systems include a 3rd generation partnership project (3GPP) or 3GPP2 system.

The embodiments of the present disclosure are applicable not only to the various radio access systems but also to all technical fields, to which the various radio access systems are applied. Further, the proposed methods are applicable to mmWave and THzWave communication systems using ultrahigh frequency bands.

Additionally, the embodiments of the present disclosure are applicable to various applications such as autonomous vehicles, drones and the like. 

1-19. (canceled)
 20. A method of operating by a terminal in a wireless communication system, the method comprising: receiving a first system information block (SIB) from a first base station, the received first SIB including at least one first parameter; receiving first information from the first base station; and performing cell reselection for a second base station based on at least one second parameter, wherein the at least one first parameter is updated to the at least one second parameter in which the first information is reflected by learning of a cell reselection learning model.
 21. The method of claim 20, wherein the at least one first parameter is generated by the first base station, wherein the first base station receives parameter information related to the cell reselection learning model from a plurality of terminals, and wherein the at least one first parameter is generated based on the parameter information related to the cell reselection learning model received from the plurality of terminals and is transmitted to the terminal through the first SIB.
 22. The method of claim 20, wherein the at least one second parameter is transmitted to the second base station, wherein cell reselection related information generated by the second base station based on the at least one second parameter is received through a second SIB, and wherein the cell reselection for the second base station is performed based on the cell reselection related information received through the second SIB.
 23. The method of claim 22, wherein the at least one second parameter is transmitted to the second base station through a random access channel (RACH).
 24. The method of claim 20, wherein the first information comprises channel state information (CSI).
 25. The method of claim 20, further comprises receiving information indicating whether to use the cell reselection learning model from the first base station.
 26. The method of claim 25, wherein the terminal updates the at least one second parameter only when the information indicating whether to use the cell reselection learning model indicates that the cell reselection learning model is used.
 27. The method of claim 20, further comprises receiving a weight from the first base station, wherein the weight is a value for minimizing a difference between a value measured by the first base station and the at least one first parameter, and wherein, when updating the at least one first parameter to the at least one second parameter, the weight is further considered.
 28. The method of claim 20, wherein the cell reselection learning model is a model trained based on a beta distribution.
 29. The method of claim 28, wherein the reselecting the second base station based on the at least one second parameter comprises reselecting the second base station based on a maximum value of values obtained by randomly sampling the beta distribution.
 30. The method of claim 29, wherein parameters of the beta distribution and α and β, and wherein α+1 operation is performed based on receive power of the terminal being maintained and increased after cell reselection, and wherein β+1 operation is performed based on the receive power being decreased after cell reselection.
 31. The method of claim 30, further comprising: updating the beta distribution based on the operation; and transmitting the at least one second parameter, on which the operation is performed, to the second base station.
 32. An apparatus in a wireless communication system, comprising: a wireless transceiver; and a processor, wherein the processor is configured to: control the wireless transceiver to receive a first system information block (SIB) from a first base station, the received first SIB including at least one first parameter, control the wireless transceiver to receive first information from the first base station, and reselect a second base station based on at least one second parameter, wherein the at least one first parameter is updated to the at least one second parameter in which the first information is reflected by learning of a cell reselection learning model.
 33. The apparatus of claim 32, wherein the at least one first parameter is generated by the first base station, wherein the first base station receives parameter information related to the cell reselection learning model from a plurality of terminals, and wherein the at least one first parameter is generated based on the parameter information related to the cell reselection learning model received from the plurality of terminals and is transmitted using the transceiver through the first SIB.
 34. The apparatus of claim 32, wherein the processor is further configured to: control the transceiver to transmit at least one second parameter to the second base station, and control the transceiver to receive, through a second SIB, cell reselection related information generated by the second base station based on the second parameter, and perform the cell reselection for the second base station based on the cell reselection related information included in the received second SIB.
 35. A base station in a wireless communication system, the base station comprising: a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: control the transceiver to transmit a system information block (SIB) including at least one first parameter to a first terminal, and control the transceiver to transmit first information to the first terminal, wherein the at least one first parameter is generated based on parameter information related to a cell reselection model received from a plurality of terminals.
 36. The apparatus of claim 32, wherein the at least one second parameter is transmitted to the second base station through a random access channel (RACH).
 37. The apparatus of claim 32, wherein the first information comprises channel state information (CSI).
 38. The apparatus of claim 32, wherein the processor is further configured to: control the wireless transceiver to receive information indicating whether to use the cell reselection learning model from the first base station, and update the at least one second parameter only when the information indicating whether to use the cell reselection learning model indicates that the cell reselection learning model is used.
 39. The apparatus of claim 32, wherein the processor is further configured to control the wireless transceiver to receive a weight from the first base station, wherein the weight is a value for minimizing a difference between a value measured by the first base station and the at least one first parameter, and wherein, when updating the at least one first parameter to the at least one second parameter, the weight is further considered. 